diff --git a/book/source/adv/certificates.md b/book/source/adv/certificates.md
index 8020b90..135baa2 100644
--- a/book/source/adv/certificates.md
+++ b/book/source/adv/certificates.md
@@ -195,7 +195,6 @@ gpg --export-options export-minimal,export-clean,no-export-attributes \
     --export-filter keep-uid=mbox=wiktor@metacode.biz \
     --export-filter 'drop-subkey=expired -t || revoked -t || usage =~ a' \
     --export wiktor@metacode.biz
-
 ```
 The process significantly reduces the certificate size from 152,322 bytes to just 3,771 bytes, demonstrating a substantial decrease in size by over 40 times. Such minimization is particularly crucial in contexts with strict size limitations, like embedding certificate data in email headers.