Brackets are now allowed, after a small hack in the processing of the
docs-on-web.

doc/crypto/BIO_s_bio.pod

diff --git a/doc/crypto/BIO_s_bio.pod b/doc/crypto/BIO_s_bio.pod
index 592cab4..8d0a55a 100644
--- a/doc/crypto/BIO_s_bio.pod
+++ b/doc/crypto/BIO_s_bio.pod
@@ -126,7 +126,7 @@
 B<bio1> and B<bio2>, or 0 on failure, with NULL pointers stored into the
 locations for B<bio1> and B<bio2>. Check the error stack for more information.
 
-XXXXX: More return values need to be added here
+[XXXXX: More return values need to be added here]
 
 =head1 EXAMPLE