Custom BBCodes are extra "options" to the command menu on PHPBB sort of like the "Bold", "Quote", "Code" and "Img" Commands already there.
My Suggestion is to add a few more that can be used to enhance posts such as: "Left Align', "Right Align" "Center Align" "Spoilers" and "Youtube Video"
These commands can be easily setup in the Admin CP and can really add some flare to posts especially ones made by admins.
Below i provide a link showing how to add them along with the codes themselves
http://www.phpbb.com/kb/article/adding- ... in-phpbb3/
Thankyou for Reading
-Trying to help wherever i can
~ Pavilion