1 BBCodes for phpbb3
Copy the directory for the desired language like de from htdocs/styles/lucid_lime/imageset/ into your theme (for example htdocs/styles/tranquil_teal/imageset.
Pinned here as I always forget that.
3 Themes I like
4 Piwik with Phpbb3
5 Q&A Captcha for phpBB
Because I always forget how to do that: https://www.phpbb.com/kb/article/how-to-configure-q+a-captcha/.