Find and document missing documentation
Once upon a time we had a script that checked for missing documentation. It scoured the php-src and determined which functions were missing from the PHP manual. Let's reintroduce this, and expand the idea to include methods, constants and ini settings.
Scouring php-src can be difficult.
Some missing functions are intentionally not documented (php_egg_logo_guid(), leak(), …), as are some aliases.
Some definitions require specific FLAGS at compile time
Some definitions are commented out within php-src
Using a local compiled PHP will miss some some information (as not everything is compiled in) but maybe it's a good start (and simple)