Good Encryption Practices

For practical purposes I don't know anything about encryption; I'll just get that out of the way now.

The parent warns against messages with similar formats, exchange of pleasantries or signatures. In particular, it warns against sending HTML-formatted data (e-mails).

Encrypted data is sent all day long, with message contents in HTML format over SSL/TLS.

Would this article be better named "Good GPG Encryption Practices"?

-If so, could GPG be improved to share the characteristics of SSL/TLS or does it already have that support with some message types?

-If not, why don't we see more attacks on HTTPS traffic?