diff --git a/sop-java-picocli/src/test/java/sop/cli/picocli/SOPTest.java b/sop-java-picocli/src/test/java/sop/cli/picocli/SOPTest.java
index 5727a47..9ca88da 100644
--- a/sop-java-picocli/src/test/java/sop/cli/picocli/SOPTest.java
+++ b/sop-java-picocli/src/test/java/sop/cli/picocli/SOPTest.java
@@ -14,6 +14,7 @@ import java.util.List;
 import com.ginsberg.junit.exit.ExpectSystemExitWithStatus;
 import org.junit.jupiter.api.Test;
 import sop.SOP;
+import sop.exception.SOPGPException;
 import sop.operation.Armor;
 import sop.operation.Dearmor;
 import sop.operation.Decrypt;
@@ -30,7 +31,7 @@ import sop.operation.Version;
 public class SOPTest {
 
     @Test
-    @ExpectSystemExitWithStatus(69)
+    @ExpectSystemExitWithStatus(SOPGPException.UnsupportedSubcommand.EXIT_CODE)
     public void assertExitOnInvalidSubcommand() {
         SOP sop = mock(SOP.class);
         SopCLI.setSopInstance(sop);
@@ -125,7 +126,8 @@ public class SOPTest {
 
         for (String[] command : commands) {
             int exit = SopCLI.execute(command);
-            assertEquals(69, exit, "Unexpected exit code for non-implemented command " + Arrays.toString(command) + ": " + exit);
+            assertEquals(SOPGPException.UnsupportedSubcommand.EXIT_CODE, exit,
+                    "Unexpected exit code for non-implemented command " + Arrays.toString(command) + ": " + exit);
         }
     }
 }
diff --git a/sop-java-picocli/src/test/java/sop/cli/picocli/commands/ArmorCmdTest.java b/sop-java-picocli/src/test/java/sop/cli/picocli/commands/ArmorCmdTest.java
index e54597d..6bdbe7f 100644
--- a/sop-java-picocli/src/test/java/sop/cli/picocli/commands/ArmorCmdTest.java
+++ b/sop-java-picocli/src/test/java/sop/cli/picocli/commands/ArmorCmdTest.java
@@ -62,13 +62,13 @@ public class ArmorCmdTest {
     }
 
     @Test
-    @ExpectSystemExitWithStatus(37)
+    @ExpectSystemExitWithStatus(SOPGPException.UnsupportedOption.EXIT_CODE)
     public void assertThrowsForInvalidLabel() {
         SopCLI.main(new String[] {"armor", "--label", "Invalid"});
     }
 
     @Test
-    @ExpectSystemExitWithStatus(37)
+    @ExpectSystemExitWithStatus(SOPGPException.UnsupportedOption.EXIT_CODE)
     public void ifLabelsUnsupportedExit37() throws SOPGPException.UnsupportedOption {
         when(armor.label(any())).thenThrow(new SOPGPException.UnsupportedOption("Custom Armor labels are not supported."));
 
@@ -76,7 +76,7 @@ public class ArmorCmdTest {
     }
 
     @Test
-    @ExpectSystemExitWithStatus(41)
+    @ExpectSystemExitWithStatus(SOPGPException.BadData.EXIT_CODE)
     public void ifBadDataExit41() throws SOPGPException.BadData, IOException {
         when(armor.data((InputStream) any())).thenThrow(new SOPGPException.BadData(new IOException()));
 
diff --git a/sop-java-picocli/src/test/java/sop/cli/picocli/commands/DearmorCmdTest.java b/sop-java-picocli/src/test/java/sop/cli/picocli/commands/DearmorCmdTest.java
index aaad201..875eaed 100644
--- a/sop-java-picocli/src/test/java/sop/cli/picocli/commands/DearmorCmdTest.java
+++ b/sop-java-picocli/src/test/java/sop/cli/picocli/commands/DearmorCmdTest.java
@@ -53,7 +53,7 @@ public class DearmorCmdTest {
     }
 
     @Test
-    @ExpectSystemExitWithStatus(41)
+    @ExpectSystemExitWithStatus(SOPGPException.BadData.EXIT_CODE)
     public void assertBadDataCausesExit41() throws IOException, SOPGPException.BadData {
         when(dearmor.data((InputStream) any())).thenThrow(new SOPGPException.BadData(new IOException("invalid armor")));
         SopCLI.main(new String[] {"dearmor"});
diff --git a/sop-java-picocli/src/test/java/sop/cli/picocli/commands/DecryptCmdTest.java b/sop-java-picocli/src/test/java/sop/cli/picocli/commands/DecryptCmdTest.java
index 5b5563e..3da2d09 100644
--- a/sop-java-picocli/src/test/java/sop/cli/picocli/commands/DecryptCmdTest.java
+++ b/sop-java-picocli/src/test/java/sop/cli/picocli/commands/DecryptCmdTest.java
@@ -74,21 +74,21 @@ public class DecryptCmdTest {
     }
 
     @Test
-    @ExpectSystemExitWithStatus(19)
+    @ExpectSystemExitWithStatus(SOPGPException.MissingArg.EXIT_CODE)
     public void missingArgumentsExceptionCausesExit19() throws SOPGPException.MissingArg, SOPGPException.BadData, SOPGPException.CannotDecrypt, IOException {
         when(decrypt.ciphertext((InputStream) any())).thenThrow(new SOPGPException.MissingArg("Missing arguments."));
         SopCLI.main(new String[] {"decrypt"});
     }
 
     @Test
-    @ExpectSystemExitWithStatus(41)
+    @ExpectSystemExitWithStatus(SOPGPException.BadData.EXIT_CODE)
     public void badDataExceptionCausesExit41() throws SOPGPException.MissingArg, SOPGPException.BadData, SOPGPException.CannotDecrypt, IOException {
         when(decrypt.ciphertext((InputStream) any())).thenThrow(new SOPGPException.BadData(new IOException()));
         SopCLI.main(new String[] {"decrypt"});
     }
 
     @Test
-    @ExpectSystemExitWithStatus(31)
+    @ExpectSystemExitWithStatus(SOPGPException.PasswordNotHumanReadable.EXIT_CODE)
     public void assertNotHumanReadablePasswordCausesExit31() throws SOPGPException.PasswordNotHumanReadable,
             SOPGPException.UnsupportedOption, IOException {
         File passwordFile = TestFileUtil.writeTempStringFile("pretendThisIsNotReadable");
@@ -104,7 +104,7 @@ public class DecryptCmdTest {
     }
 
     @Test
-    @ExpectSystemExitWithStatus(37)
+    @ExpectSystemExitWithStatus(SOPGPException.UnsupportedOption.EXIT_CODE)
     public void assertUnsupportedWithPasswordCausesExit37() throws SOPGPException.PasswordNotHumanReadable, SOPGPException.UnsupportedOption, IOException {
         File passwordFile = TestFileUtil.writeTempStringFile("swordfish");
         when(decrypt.withPassword(any())).thenThrow(new SOPGPException.UnsupportedOption("Decrypting with password not supported."));
@@ -158,21 +158,21 @@ public class DecryptCmdTest {
     }
 
     @Test
-    @ExpectSystemExitWithStatus(37)
+    @ExpectSystemExitWithStatus(SOPGPException.UnsupportedOption.EXIT_CODE)
     public void assertUnsupportedNotAfterCausesExit37() throws SOPGPException.UnsupportedOption {
         when(decrypt.verifyNotAfter(any())).thenThrow(new SOPGPException.UnsupportedOption("Setting upper signature date boundary not supported."));
         SopCLI.main(new String[] {"decrypt", "--not-after", "now"});
     }
 
     @Test
-    @ExpectSystemExitWithStatus(37)
+    @ExpectSystemExitWithStatus(SOPGPException.UnsupportedOption.EXIT_CODE)
     public void assertUnsupportedNotBeforeCausesExit37() throws SOPGPException.UnsupportedOption {
         when(decrypt.verifyNotBefore(any())).thenThrow(new SOPGPException.UnsupportedOption("Setting lower signature date boundary not supported."));
         SopCLI.main(new String[] {"decrypt", "--not-before", "now"});
     }
 
     @Test
-    @ExpectSystemExitWithStatus(59)
+    @ExpectSystemExitWithStatus(SOPGPException.OutputExists.EXIT_CODE)
     public void assertExistingSessionKeyOutFileCausesExit59() throws IOException {
         File tempFile = File.createTempFile("existing-session-key-", ".tmp");
         tempFile.deleteOnExit();
@@ -180,7 +180,7 @@ public class DecryptCmdTest {
     }
 
     @Test
-    @ExpectSystemExitWithStatus(37)
+    @ExpectSystemExitWithStatus(SOPGPException.UnsupportedOption.EXIT_CODE)
     public void assertWhenSessionKeyCannotBeExtractedExit37() throws IOException {
         Path tempDir = Files.createTempDirectory("session-key-out-dir");
         File tempFile = new File(tempDir.toFile(), "session-key");
@@ -222,14 +222,14 @@ public class DecryptCmdTest {
     }
 
     @Test
-    @ExpectSystemExitWithStatus(29)
+    @ExpectSystemExitWithStatus(SOPGPException.CannotDecrypt.EXIT_CODE)
     public void assertUnableToDecryptExceptionResultsInExit29() throws SOPGPException.CannotDecrypt, SOPGPException.MissingArg, SOPGPException.BadData, IOException {
         when(decrypt.ciphertext((InputStream) any())).thenThrow(new SOPGPException.CannotDecrypt());
         SopCLI.main(new String[] {"decrypt"});
     }
 
     @Test
-    @ExpectSystemExitWithStatus(3)
+    @ExpectSystemExitWithStatus(SOPGPException.NoSignature.EXIT_CODE)
     public void assertNoSignatureExceptionCausesExit3() throws SOPGPException.CannotDecrypt, SOPGPException.MissingArg, SOPGPException.BadData, IOException {
         when(decrypt.ciphertext((InputStream) any())).thenReturn(new ReadyWithResult<DecryptionResult>() {
             @Override
@@ -241,7 +241,7 @@ public class DecryptCmdTest {
     }
 
     @Test
-    @ExpectSystemExitWithStatus(41)
+    @ExpectSystemExitWithStatus(SOPGPException.BadData.EXIT_CODE)
     public void badDataInVerifyWithCausesExit41() throws IOException, SOPGPException.BadData {
         when(decrypt.verifyWithCert((InputStream) any())).thenThrow(new SOPGPException.BadData(new IOException()));
         File tempFile = File.createTempFile("verify-with-", ".tmp");
@@ -249,13 +249,13 @@ public class DecryptCmdTest {
     }
 
     @Test
-    @ExpectSystemExitWithStatus(61)
+    @ExpectSystemExitWithStatus(SOPGPException.MissingInput.EXIT_CODE)
     public void unexistentCertFileCausesExit61() {
         SopCLI.main(new String[] {"decrypt", "--verify-with", "invalid"});
     }
 
     @Test
-    @ExpectSystemExitWithStatus(59)
+    @ExpectSystemExitWithStatus(SOPGPException.OutputExists.EXIT_CODE)
     public void existingVerifyOutCausesExit59() throws IOException {
         File certFile = File.createTempFile("existing-verify-out-cert", ".asc");
         File existingVerifyOut = File.createTempFile("existing-verify-out", ".tmp");
@@ -315,7 +315,7 @@ public class DecryptCmdTest {
     }
 
     @Test
-    @ExpectSystemExitWithStatus(41)
+    @ExpectSystemExitWithStatus(SOPGPException.BadData.EXIT_CODE)
     public void assertBadDataInKeysResultsInExit41() throws SOPGPException.KeyIsProtected, SOPGPException.UnsupportedAsymmetricAlgo, SOPGPException.BadData, IOException {
         when(decrypt.withKey((InputStream) any())).thenThrow(new SOPGPException.BadData(new IOException()));
         File tempKeyFile = File.createTempFile("key-", ".tmp");
@@ -323,13 +323,13 @@ public class DecryptCmdTest {
     }
 
     @Test
-    @ExpectSystemExitWithStatus(61)
+    @ExpectSystemExitWithStatus(SOPGPException.MissingInput.EXIT_CODE)
     public void assertKeyFileNotFoundCausesExit61() {
         SopCLI.main(new String[] {"decrypt", "nonexistent-key"});
     }
 
     @Test
-    @ExpectSystemExitWithStatus(67)
+    @ExpectSystemExitWithStatus(SOPGPException.KeyIsProtected.EXIT_CODE)
     public void assertProtectedKeyCausesExit67() throws IOException, SOPGPException.KeyIsProtected, SOPGPException.UnsupportedAsymmetricAlgo, SOPGPException.BadData {
         when(decrypt.withKey((InputStream) any())).thenThrow(new SOPGPException.KeyIsProtected());
         File tempKeyFile = File.createTempFile("key-", ".tmp");
@@ -337,7 +337,7 @@ public class DecryptCmdTest {
     }
 
     @Test
-    @ExpectSystemExitWithStatus(13)
+    @ExpectSystemExitWithStatus(SOPGPException.UnsupportedAsymmetricAlgo.EXIT_CODE)
     public void assertUnsupportedAlgorithmExceptionCausesExit13() throws SOPGPException.KeyIsProtected, SOPGPException.UnsupportedAsymmetricAlgo, SOPGPException.BadData, IOException {
         when(decrypt.withKey((InputStream) any())).thenThrow(new SOPGPException.UnsupportedAsymmetricAlgo("Unsupported asymmetric algorithm.", new IOException()));
         File tempKeyFile = File.createTempFile("key-", ".tmp");
@@ -345,19 +345,19 @@ public class DecryptCmdTest {
     }
 
     @Test
-    @ExpectSystemExitWithStatus(61)
+    @ExpectSystemExitWithStatus(SOPGPException.MissingInput.EXIT_CODE)
     public void assertMissingPassphraseFileCausesExit61() {
         SopCLI.main(new String[] {"decrypt", "--with-password", "missing"});
     }
 
     @Test
-    @ExpectSystemExitWithStatus(61)
+    @ExpectSystemExitWithStatus(SOPGPException.MissingInput.EXIT_CODE)
     public void assertMissingSessionKeyFileCausesExit61() {
         SopCLI.main(new String[] {"decrypt", "--with-session-key", "missing"});
     }
 
     @Test
-    @ExpectSystemExitWithStatus(23)
+    @ExpectSystemExitWithStatus(SOPGPException.IncompleteVerification.EXIT_CODE)
     public void verifyOutWithoutVerifyWithCausesExit23() {
         SopCLI.main(new String[] {"decrypt", "--verify-out", "out.file"});
     }
diff --git a/sop-java-picocli/src/test/java/sop/cli/picocli/commands/EncryptCmdTest.java b/sop-java-picocli/src/test/java/sop/cli/picocli/commands/EncryptCmdTest.java
index 68643f1..73ec9cb 100644
--- a/sop-java-picocli/src/test/java/sop/cli/picocli/commands/EncryptCmdTest.java
+++ b/sop-java-picocli/src/test/java/sop/cli/picocli/commands/EncryptCmdTest.java
@@ -48,13 +48,13 @@ public class EncryptCmdTest {
     }
 
     @Test
-    @ExpectSystemExitWithStatus(19)
+    @ExpectSystemExitWithStatus(SOPGPException.MissingArg.EXIT_CODE)
     public void missingBothPasswordAndCertFileCauseExit19() {
         SopCLI.main(new String[] {"encrypt", "--no-armor"});
     }
 
     @Test
-    @ExpectSystemExitWithStatus(37)
+    @ExpectSystemExitWithStatus(SOPGPException.UnsupportedOption.EXIT_CODE)
     public void as_unsupportedEncryptAsCausesExit37() throws SOPGPException.UnsupportedOption {
         when(encrypt.mode(any())).thenThrow(new SOPGPException.UnsupportedOption("Setting encryption mode not supported."));
 
@@ -62,7 +62,7 @@ public class EncryptCmdTest {
     }
 
     @Test
-    @ExpectSystemExitWithStatus(37)
+    @ExpectSystemExitWithStatus(SOPGPException.UnsupportedOption.EXIT_CODE)
     public void as_invalidModeOptionCausesExit37() {
         SopCLI.main(new String[] {"encrypt", "--as", "invalid"});
     }
@@ -77,7 +77,7 @@ public class EncryptCmdTest {
     }
 
     @Test
-    @ExpectSystemExitWithStatus(31)
+    @ExpectSystemExitWithStatus(SOPGPException.PasswordNotHumanReadable.EXIT_CODE)
     public void withPassword_notHumanReadablePasswordCausesExit31() throws SOPGPException.PasswordNotHumanReadable, SOPGPException.UnsupportedOption, IOException {
         when(encrypt.withPassword("pretendThisIsNotReadable")).thenThrow(new SOPGPException.PasswordNotHumanReadable());
         File passwordFile = TestFileUtil.writeTempStringFile("pretendThisIsNotReadable");
@@ -85,7 +85,7 @@ public class EncryptCmdTest {
     }
 
     @Test
-    @ExpectSystemExitWithStatus(37)
+    @ExpectSystemExitWithStatus(SOPGPException.UnsupportedOption.EXIT_CODE)
     public void withPassword_unsupportedWithPasswordCausesExit37() throws SOPGPException.PasswordNotHumanReadable, SOPGPException.UnsupportedOption, IOException {
         when(encrypt.withPassword(any())).thenThrow(new SOPGPException.UnsupportedOption("Encrypting with password not supported."));
         File passwordFile = TestFileUtil.writeTempStringFile("orange");
@@ -102,13 +102,13 @@ public class EncryptCmdTest {
     }
 
     @Test
-    @ExpectSystemExitWithStatus(61)
+    @ExpectSystemExitWithStatus(SOPGPException.MissingInput.EXIT_CODE)
     public void signWith_nonExistentKeyFileCausesExit61() {
         SopCLI.main(new String[] {"encrypt", "--with-password", "admin", "--sign-with", "nonExistent.asc"});
     }
 
     @Test
-    @ExpectSystemExitWithStatus(67)
+    @ExpectSystemExitWithStatus(SOPGPException.KeyIsProtected.EXIT_CODE)
     public void signWith_keyIsProtectedCausesExit67() throws SOPGPException.KeyIsProtected, SOPGPException.UnsupportedAsymmetricAlgo, SOPGPException.KeyCannotSign, SOPGPException.BadData, IOException {
         when(encrypt.signWith((InputStream) any())).thenThrow(new SOPGPException.KeyIsProtected());
         File keyFile = File.createTempFile("sign-with", ".asc");
@@ -117,7 +117,7 @@ public class EncryptCmdTest {
     }
 
     @Test
-    @ExpectSystemExitWithStatus(13)
+    @ExpectSystemExitWithStatus(SOPGPException.UnsupportedAsymmetricAlgo.EXIT_CODE)
     public void signWith_unsupportedAsymmetricAlgoCausesExit13() throws SOPGPException.KeyIsProtected, SOPGPException.UnsupportedAsymmetricAlgo, SOPGPException.KeyCannotSign, SOPGPException.BadData, IOException {
         when(encrypt.signWith((InputStream) any())).thenThrow(new SOPGPException.UnsupportedAsymmetricAlgo("Unsupported asymmetric algorithm.", new Exception()));
         File keyFile = File.createTempFile("sign-with", ".asc");
@@ -126,7 +126,7 @@ public class EncryptCmdTest {
     }
 
     @Test
-    @ExpectSystemExitWithStatus(79)
+    @ExpectSystemExitWithStatus(SOPGPException.KeyCannotSign.EXIT_CODE)
     public void signWith_certCannotSignCausesExit79() throws IOException, SOPGPException.KeyIsProtected, SOPGPException.UnsupportedAsymmetricAlgo, SOPGPException.KeyCannotSign, SOPGPException.BadData {
         when(encrypt.signWith((InputStream) any())).thenThrow(new SOPGPException.KeyCannotSign());
         File keyFile = File.createTempFile("sign-with", ".asc");
@@ -135,7 +135,7 @@ public class EncryptCmdTest {
     }
 
     @Test
-    @ExpectSystemExitWithStatus(41)
+    @ExpectSystemExitWithStatus(SOPGPException.BadData.EXIT_CODE)
     public void signWith_badDataCausesExit41() throws SOPGPException.KeyIsProtected, SOPGPException.UnsupportedAsymmetricAlgo, SOPGPException.KeyCannotSign, SOPGPException.BadData, IOException {
         when(encrypt.signWith((InputStream) any())).thenThrow(new SOPGPException.BadData(new IOException()));
         File keyFile = File.createTempFile("sign-with", ".asc");
@@ -144,13 +144,13 @@ public class EncryptCmdTest {
     }
 
     @Test
-    @ExpectSystemExitWithStatus(61)
+    @ExpectSystemExitWithStatus(SOPGPException.MissingInput.EXIT_CODE)
     public void cert_nonExistentCertFileCausesExit61() {
         SopCLI.main(new String[] {"encrypt", "invalid.asc"});
     }
 
     @Test
-    @ExpectSystemExitWithStatus(13)
+    @ExpectSystemExitWithStatus(SOPGPException.UnsupportedAsymmetricAlgo.EXIT_CODE)
     public void cert_unsupportedAsymmetricAlgorithmCausesExit13() throws IOException, SOPGPException.UnsupportedAsymmetricAlgo, SOPGPException.CertCannotEncrypt, SOPGPException.BadData {
         when(encrypt.withCert((InputStream) any())).thenThrow(new SOPGPException.UnsupportedAsymmetricAlgo("Unsupported asymmetric algorithm.", new Exception()));
         File certFile = File.createTempFile("cert", ".asc");
@@ -158,7 +158,7 @@ public class EncryptCmdTest {
     }
 
     @Test
-    @ExpectSystemExitWithStatus(17)
+    @ExpectSystemExitWithStatus(SOPGPException.CertCannotEncrypt.EXIT_CODE)
     public void cert_certCannotEncryptCausesExit17() throws IOException, SOPGPException.UnsupportedAsymmetricAlgo, SOPGPException.CertCannotEncrypt, SOPGPException.BadData {
         when(encrypt.withCert((InputStream) any())).thenThrow(new SOPGPException.CertCannotEncrypt("Certificate cannot encrypt.", new Exception()));
         File certFile = File.createTempFile("cert", ".asc");
@@ -166,7 +166,7 @@ public class EncryptCmdTest {
     }
 
     @Test
-    @ExpectSystemExitWithStatus(41)
+    @ExpectSystemExitWithStatus(SOPGPException.BadData.EXIT_CODE)
     public void cert_badDataCausesExit41() throws IOException, SOPGPException.UnsupportedAsymmetricAlgo, SOPGPException.CertCannotEncrypt, SOPGPException.BadData {
         when(encrypt.withCert((InputStream) any())).thenThrow(new SOPGPException.BadData(new IOException()));
         File certFile = File.createTempFile("cert", ".asc");
diff --git a/sop-java-picocli/src/test/java/sop/cli/picocli/commands/ExtractCertCmdTest.java b/sop-java-picocli/src/test/java/sop/cli/picocli/commands/ExtractCertCmdTest.java
index 382fe30..12f837d 100644
--- a/sop-java-picocli/src/test/java/sop/cli/picocli/commands/ExtractCertCmdTest.java
+++ b/sop-java-picocli/src/test/java/sop/cli/picocli/commands/ExtractCertCmdTest.java
@@ -68,7 +68,7 @@ public class ExtractCertCmdTest {
     }
 
     @Test
-    @ExpectSystemExitWithStatus(41)
+    @ExpectSystemExitWithStatus(SOPGPException.BadData.EXIT_CODE)
     public void key_badDataCausesExit41() throws IOException, SOPGPException.BadData {
         when(extractCert.key((InputStream) any())).thenThrow(new SOPGPException.BadData(new IOException()));
         SopCLI.main(new String[] {"extract-cert"});
diff --git a/sop-java-picocli/src/test/java/sop/cli/picocli/commands/GenerateKeyCmdTest.java b/sop-java-picocli/src/test/java/sop/cli/picocli/commands/GenerateKeyCmdTest.java
index 643cf36..e7ebf1a 100644
--- a/sop-java-picocli/src/test/java/sop/cli/picocli/commands/GenerateKeyCmdTest.java
+++ b/sop-java-picocli/src/test/java/sop/cli/picocli/commands/GenerateKeyCmdTest.java
@@ -69,7 +69,7 @@ public class GenerateKeyCmdTest {
     }
 
     @Test
-    @ExpectSystemExitWithStatus(19)
+    @ExpectSystemExitWithStatus(SOPGPException.MissingArg.EXIT_CODE)
     public void missingArgumentCausesExit19() throws SOPGPException.UnsupportedAsymmetricAlgo, SOPGPException.MissingArg, IOException {
         // TODO: RFC4880-bis and the current Stateless OpenPGP CLI spec allow keys to have no user-ids,
         //  so we might want to change this test in the future.
@@ -78,7 +78,7 @@ public class GenerateKeyCmdTest {
     }
 
     @Test
-    @ExpectSystemExitWithStatus(13)
+    @ExpectSystemExitWithStatus(SOPGPException.UnsupportedAsymmetricAlgo.EXIT_CODE)
     public void unsupportedAsymmetricAlgorithmCausesExit13() throws SOPGPException.UnsupportedAsymmetricAlgo, SOPGPException.MissingArg, IOException {
         when(generateKey.generate()).thenThrow(new SOPGPException.UnsupportedAsymmetricAlgo("Unsupported asymmetric algorithm.", new Exception()));
         SopCLI.main(new String[] {"generate-key", "Alice"});
diff --git a/sop-java-picocli/src/test/java/sop/cli/picocli/commands/SignCmdTest.java b/sop-java-picocli/src/test/java/sop/cli/picocli/commands/SignCmdTest.java
index 6be8d9b..3b96012 100644
--- a/sop-java-picocli/src/test/java/sop/cli/picocli/commands/SignCmdTest.java
+++ b/sop-java-picocli/src/test/java/sop/cli/picocli/commands/SignCmdTest.java
@@ -57,40 +57,40 @@ public class SignCmdTest {
     }
 
     @Test
-    @ExpectSystemExitWithStatus(37)
+    @ExpectSystemExitWithStatus(SOPGPException.UnsupportedOption.EXIT_CODE)
     public void as_invalidOptionCausesExit37() {
         SopCLI.main(new String[] {"sign", "--as", "Invalid", keyFile.getAbsolutePath()});
     }
 
     @Test
-    @ExpectSystemExitWithStatus(37)
+    @ExpectSystemExitWithStatus(SOPGPException.UnsupportedOption.EXIT_CODE)
     public void as_unsupportedOptionCausesExit37() throws SOPGPException.UnsupportedOption {
         when(detachedSign.mode(any())).thenThrow(new SOPGPException.UnsupportedOption("Setting signing mode not supported."));
         SopCLI.main(new String[] {"sign", "--as", "binary", keyFile.getAbsolutePath()});
     }
 
     @Test
-    @ExpectSystemExitWithStatus(61)
+    @ExpectSystemExitWithStatus(SOPGPException.MissingInput.EXIT_CODE)
     public void key_nonExistentKeyFileCausesExit61() {
         SopCLI.main(new String[] {"sign", "invalid.asc"});
     }
 
     @Test
-    @ExpectSystemExitWithStatus(67)
+    @ExpectSystemExitWithStatus(SOPGPException.KeyIsProtected.EXIT_CODE)
     public void key_keyIsProtectedCausesExit67() throws SOPGPException.KeyIsProtected, IOException, SOPGPException.BadData {
         when(detachedSign.key((InputStream) any())).thenThrow(new SOPGPException.KeyIsProtected());
         SopCLI.main(new String[] {"sign", keyFile.getAbsolutePath()});
     }
 
     @Test
-    @ExpectSystemExitWithStatus(41)
+    @ExpectSystemExitWithStatus(SOPGPException.BadData.EXIT_CODE)
     public void key_badDataCausesExit41() throws SOPGPException.KeyIsProtected, IOException, SOPGPException.BadData {
         when(detachedSign.key((InputStream) any())).thenThrow(new SOPGPException.BadData(new IOException()));
         SopCLI.main(new String[] {"sign", keyFile.getAbsolutePath()});
     }
 
     @Test
-    @ExpectSystemExitWithStatus(19)
+    @ExpectSystemExitWithStatus(SOPGPException.MissingArg.EXIT_CODE)
     public void key_missingKeyFileCausesExit19() {
         SopCLI.main(new String[] {"sign"});
     }
@@ -120,7 +120,7 @@ public class SignCmdTest {
     }
 
     @Test
-    @ExpectSystemExitWithStatus(53)
+    @ExpectSystemExitWithStatus(SOPGPException.ExpectedText.EXIT_CODE)
     public void data_expectedTextExceptionCausesExit53() throws IOException, SOPGPException.ExpectedText {
         when(detachedSign.data((InputStream) any())).thenThrow(new SOPGPException.ExpectedText());
         SopCLI.main(new String[] {"sign", keyFile.getAbsolutePath()});
diff --git a/sop-java-picocli/src/test/java/sop/cli/picocli/commands/VerifyCmdTest.java b/sop-java-picocli/src/test/java/sop/cli/picocli/commands/VerifyCmdTest.java
index e0e2e07..c33cf74 100644
--- a/sop-java-picocli/src/test/java/sop/cli/picocli/commands/VerifyCmdTest.java
+++ b/sop-java-picocli/src/test/java/sop/cli/picocli/commands/VerifyCmdTest.java
@@ -93,7 +93,7 @@ public class VerifyCmdTest {
     }
 
     @Test
-    @ExpectSystemExitWithStatus(37)
+    @ExpectSystemExitWithStatus(SOPGPException.UnsupportedOption.EXIT_CODE)
     public void notAfter_unsupportedOptionCausesExit37() throws SOPGPException.UnsupportedOption {
         when(detachedVerify.notAfter(any())).thenThrow(new SOPGPException.UnsupportedOption("Setting upper signature date boundary not supported."));
         SopCLI.main(new String[] {"verify", "--not-after", "2019-10-29T18:36:45Z", signature.getAbsolutePath(), cert.getAbsolutePath()});
@@ -120,7 +120,7 @@ public class VerifyCmdTest {
     }
 
     @Test
-    @ExpectSystemExitWithStatus(37)
+    @ExpectSystemExitWithStatus(SOPGPException.UnsupportedOption.EXIT_CODE)
     public void notBefore_unsupportedOptionCausesExit37() throws SOPGPException.UnsupportedOption {
         when(detachedVerify.notBefore(any())).thenThrow(new SOPGPException.UnsupportedOption("Setting lower signature date boundary not supported."));
         SopCLI.main(new String[] {"verify", "--not-before", "2019-10-29T18:36:45Z", signature.getAbsolutePath(), cert.getAbsolutePath()});
@@ -138,40 +138,40 @@ public class VerifyCmdTest {
     }
 
     @Test
-    @ExpectSystemExitWithStatus(61)
+    @ExpectSystemExitWithStatus(SOPGPException.MissingInput.EXIT_CODE)
     public void cert_fileNotFoundCausesExit61() {
         SopCLI.main(new String[] {"verify", signature.getAbsolutePath(), "invalid.asc"});
     }
 
     @Test
-    @ExpectSystemExitWithStatus(41)
+    @ExpectSystemExitWithStatus(SOPGPException.BadData.EXIT_CODE)
     public void cert_badDataCausesExit41() throws SOPGPException.BadData, IOException {
         when(detachedVerify.cert((InputStream) any())).thenThrow(new SOPGPException.BadData(new IOException()));
         SopCLI.main(new String[] {"verify", signature.getAbsolutePath(), cert.getAbsolutePath()});
     }
 
     @Test
-    @ExpectSystemExitWithStatus(61)
+    @ExpectSystemExitWithStatus(SOPGPException.MissingInput.EXIT_CODE)
     public void signature_fileNotFoundCausesExit61() {
         SopCLI.main(new String[] {"verify", "invalid.sig", cert.getAbsolutePath()});
     }
 
     @Test
-    @ExpectSystemExitWithStatus(41)
+    @ExpectSystemExitWithStatus(SOPGPException.BadData.EXIT_CODE)
     public void signature_badDataCausesExit41() throws SOPGPException.BadData, IOException {
         when(detachedVerify.signatures((InputStream) any())).thenThrow(new SOPGPException.BadData(new IOException()));
         SopCLI.main(new String[] {"verify", signature.getAbsolutePath(), cert.getAbsolutePath()});
     }
 
     @Test
-    @ExpectSystemExitWithStatus(3)
+    @ExpectSystemExitWithStatus(SOPGPException.NoSignature.EXIT_CODE)
     public void data_noSignaturesCausesExit3() throws SOPGPException.NoSignature, IOException, SOPGPException.BadData {
         when(detachedVerify.data((InputStream) any())).thenThrow(new SOPGPException.NoSignature());
         SopCLI.main(new String[] {"verify", signature.getAbsolutePath(), cert.getAbsolutePath()});
     }
 
     @Test
-    @ExpectSystemExitWithStatus(41)
+    @ExpectSystemExitWithStatus(SOPGPException.BadData.EXIT_CODE)
     public void data_badDataCausesExit41() throws SOPGPException.NoSignature, IOException, SOPGPException.BadData {
         when(detachedVerify.data((InputStream) any())).thenThrow(new SOPGPException.BadData(new IOException()));
         SopCLI.main(new String[] {"verify", signature.getAbsolutePath(), cert.getAbsolutePath()});
diff --git a/sop-java-picocli/src/test/java/sop/cli/picocli/commands/VersionCmdTest.java b/sop-java-picocli/src/test/java/sop/cli/picocli/commands/VersionCmdTest.java
index d11352d..e284e35 100644
--- a/sop-java-picocli/src/test/java/sop/cli/picocli/commands/VersionCmdTest.java
+++ b/sop-java-picocli/src/test/java/sop/cli/picocli/commands/VersionCmdTest.java
@@ -14,6 +14,7 @@ import org.junit.jupiter.api.BeforeEach;
 import org.junit.jupiter.api.Test;
 import sop.SOP;
 import sop.cli.picocli.SopCLI;
+import sop.exception.SOPGPException;
 import sop.operation.Version;
 
 public class VersionCmdTest {
@@ -53,7 +54,7 @@ public class VersionCmdTest {
     }
 
     @Test
-    @ExpectSystemExitWithStatus(37)
+    @ExpectSystemExitWithStatus(SOPGPException.UnsupportedOption.EXIT_CODE)
     public void assertInvalidOptionResultsInExit37() {
         SopCLI.main(new String[] {"version", "--invalid"});
     }
diff --git a/sop-java/src/main/java/sop/exception/SOPGPException.java b/sop-java/src/main/java/sop/exception/SOPGPException.java
index d3aef8e..eca2476 100644
--- a/sop-java/src/main/java/sop/exception/SOPGPException.java
+++ b/sop-java/src/main/java/sop/exception/SOPGPException.java
@@ -25,7 +25,7 @@ public abstract class SOPGPException extends RuntimeException {
     public abstract int getExitCode();
 
     /**
-     * No acceptable signatures found (sop verify).
+     * No acceptable signatures found (sop verify, inline-verify).
      */
     public static class NoSignature extends SOPGPException {
 
@@ -46,7 +46,7 @@ public abstract class SOPGPException extends RuntimeException {
     }
 
     /**
-     * Asymmetric algorithm unsupported (sop encrypt).
+     * Asymmetric algorithm unsupported (sop encrypt, sign, inline-sign).
      */
     public static class UnsupportedAsymmetricAlgo extends SOPGPException {
 
@@ -250,6 +250,10 @@ public abstract class SOPGPException extends RuntimeException {
             super();
         }
 
+        public KeyIsProtected(String message) {
+            super(message);
+        }
+
         public KeyIsProtected(String message, Throwable cause) {
             super(message, cause);
         }
@@ -295,8 +299,10 @@ public abstract class SOPGPException extends RuntimeException {
     }
 
     /**
-     * A indirect input parameter is a special designator (it starts with @),
-     * and a filename matching the designator is actually present.
+     * Exception that gets thrown if a special designator (starting with @) is given, but the filesystem contains
+     * a file matching the designator.
+     *
+     * E.g. <pre>@ENV:FOO</pre> is given, but <pre>./@ENV:FOO</pre> exists on the filesystem.
      */
     public static class AmbiguousInput extends SOPGPException {