There have been a lot of requests for new features. Some are achieved through the forum Admin controls, some are available as Add-ons, but many forum administrators edit the core files to do what they want if they can't do it any other way. Just look at the phpBB community support pages for code to do this or that and help when it goes wrong!
However, you have to remember what you have changed when updating to a new version (3.1.6 to 3.1.10 this year). As a general rule updating software overwrites the old files with new but with standard unedited files, so you have to remember what you have done and make the changes again. It's not as easy as you think! You may get a post later saying that clicking a link used to open a new tab or window but doesn't anymore and you realise that you haven't re-edited the core file after updating. (I know a user can set this in his browser, but some don't and it helps if set across the board.)
You not only have to remember what feature you edited or added, but where you got the code from. So be warned
So far the forum is looking good, well done, but the temptation will be to fiddle with the core files to satisfy some members.
Good luck
