Source can mean anything like an item, feat, class feature, template, magical location, spell, racial trait, domain granted power, etc. from any official material, such as Drow of the Underdark (non-core), Dragon Magazine (not a book), or Wizards of the Coast (WotC) web articles (not print).
A Hide in Plain Sight (HiPS) ability means an ability to Hide (even) while being observed AND/OR without having anything to actually hide behind.
Why I define HiPS as either or both criteria is because, generally speaking, either one sounds like (an ability) to hide in plain sight, and because there doesn't seem to be a prototypical (source of a) HiPS ability. So instead of any ability that is named "Hide in Plain Sight", I define it by the elements that are most common and popular to a HiPS ability.
Because there is no prototype, please be detailed about the HiPS ability that each source grants, such as whether it's extraordinary or supernatural, whether it requires shadow, etc..
If there is something similar enough or better, please mention it too.
Here is an example of several of my points and an example of an answer:
- the Hellbreaker prestige class (Fiendish Codex II: Tyrants of the Nine Hells, p.86) - 1st level
Mantle of Darkness (Ex): You can make Hide checks in any kind of darkness, even when observed by creatures that can see in darkness.
I want to know because I love the thrill of stealth, so I want to know how to get such a valuable stealthy ability.
If you think my question should be amended, please let me know and I will try to accommodate you.