What feats specifically benefit a character's shield use?

Question

I was building a defensively-minded cohort today when I realized that I've searched stacks of books for all the shield-boosting feats several times in the past, and decided that the Pathfinder community could benefit from a community-maintained list of shield feats.

What feats specifically benefit a character that uses a shield?

Notes for answers:

• I am not interested in feats like Dodge that boost defense in general, without the use of a shield.
• I am not interested in feats that help you overcome an opponent's shield.
• I am not interested in feats like Arcane Shield that give you a shield bonus from a source other than a physical buckler, light or heavy shield, or tower shield.
• I am interested in feats that improve shield-bashing.
• I am interested in feats that improve shields in ways besides +AC.

Answer 1

(Organized by book, then by non-bashing to bashing, then in an arbitrary order. A short description of the feats' benefits are appreciated but not required, links likewise.)

From the Core Rulebook:

• Shield Proficiency is obvious in the case of characters who aren't already trained in shield-use.
• Shield Focus gives a flat bonus to shield AC.
• Greater Shield Focus gives another flat bonus to shield AC.
• Improved Shield Bash permits the use of shield AC even after performing a shield bash.
• Shield Slam permits a free bull rush maneuver after a successful shield bash.
• Shield Master reduces two-weapon fighting penalties when using a shield as a weapon.

From the Advanced Player's Guide:

• Covering Defense gives adjacent allies a cover bonus to AC when you use the Total Defense action.
• Missile Shield permits a shield-user to occasionally negate a ranged attack against them.
• Ray Shield lets a shield user deflect a ranged touch attack, although the shield can take damage.
• Saving Shield permits a shield-user to grant an ally a bonus to AC.
• Shield Wall is a teamwork feat that allows allies with shields to boost each other's AC.
• Duck and Cover is a teamwork feat that gives a cover AC bonus against ranged attacks if your teammate has a shield, plus some reflex save options.
• Shielded Caster is a teamwork feat that gives you a bonus to concentration checks, increasing if your ally has a shield.
• Shield Specialization gives you better AC against critical hit confirmation rolls, and applies your shield bonus to your CMD with your chosen shield.
• Greater Shield Specialization gives you even more AC against critical hit confirmation rolls, and lets you negate 1 crit per day.
• Mounted Shield adds your shield bonus to your mounts AC.
• Bashing Finish gives a free shield bash after getting a crit with a weapon.

From Ultimate Combat:

• Fortified Armor Training isn't totally shield focused, but lets you break armor or shield instead of taking a critical hit

From Ultimate Magic:

• Channeled Shield Wall takes a use of Channel Energy to give a deflection bonus to AC to you and adjacent allied while using a shield.