What are the rules for called shots?

Question

1. The d20pfsrd presents variant rules for called shots here. The source information for this page claims they come from the core rules, but I can't find them in the Core Rulebook. What source can I find these rules in? Did I miss them in some Paizo book, were they carried over from 3.5e, or from somewhere else?

2. The rules presented above state that "A called shot is a single attack made as a full-round action." But the feats dealing with called shots say "Normal: You can make one called shot per round as a standard action." Which of these is true? Is a typical called shot a standard or full-round action?

Answer 1

1. The page that you linked has a copyright notice that reads "Section 15: Copyright Notice - Pathfinder Roleplaying Game Ultimate Combat". It looks like these rules are in Ultimate Combat, which is not part of the core rulebook.

2. This is a typo in the original printings that has been officially errata'd:

In the Called Shot Feats sidebar, in the Normal entry for both feats, change “standard action” to “full-round action”.