I guess we may as well include absurd FAQ entries into this thread. Here's one of paizo's infamous ass-pull retcon rulings from the PF
This looks like the kind of work (typically passive-aggressive) non-confrontational people do, the kind of people who have fragile egos and cannot straight-out say "okay psychic spellcasting was a bad idea and we're going to have to redo parts of it" and thus try to dance around discussing their problems by instead indirectly resolving some of them in a way that unsurprisingly comes with significant collateral damage.
So here a FAQ is blatantly lying about how "many elements of the game system work assuming that all spells have their own manifestations," inventing a rule out of whole cloth and pretending it has always been part of PF. The reasons for this are actually because of the defects of the new psychic spellcasting system introduced in Occult Adventures. Psychic spellcasting has been a design failure on multiple fronts, ranging from its absurd weaknesses (rolling intimidate on a psychic spellcaster disables his spellcasting, and they need to use move actions to center themselves unless they want to get destroyed by high concentration DCs, which also fucks full action spells and casting two spells in one turn, in addition to making psychics extremely bad at spellcasting under environment conditions or personal conditions that necessitate concentration checks) to its strengths that Paizo's inept playtesters never quite noticed, because Paizo scorns things like minmaxing and destructive testing over there, with the result that their content is frequently highly broken in multiple directions.
One of the things that people picked up fast about psychic spellcasting is that as a spellcaster without verbal, somatic, or material components, it is blatantly the ideal spellcaster for casting magic unnoticed, like while you're stealthed or even when you're just walking in a crowd and that it appears to be pretty much impossible to roll spellcraft on psychics (which is nothing new, alchemical casters have this side-effect too). This of course was easily abusable (unlike the normal versions of these stunts which require investments and costs in the form of eschew materials and extensive metamagics to use spells in public unnoticed, or silent spell along with invisibility to momentarily cast while invisible) and started running roughshod over non-combat encounters since psychics could effortlessly cast dozens of spells in a public setting without anyone noticing.
However, needing to openly overhaul psychic spellcasting mechanics right after its release by rewriting the component mechanics (which is strongly recommended) was a bit too embarrassing and uncomfortable for these guys, since they hate that sort of thing, so they went for the old standby of publishing a new "clarification" in a FAQ (or book, sometimes) that is totally not about the problems with psychic spellcasters by creatively interpreting new rules text out of whole cloth (in this instance by generously interpreting the presence of flavor text as some type of iron-clad universal rules text) and thus insert a "manifestation" mechanic that was never part of the CRB as a way of putting a general stop to any forms of casting spells undetected, since this way your manifestations will give you away even if you're hiding while spellcasting and even if you're using SLAs and you can't stop people from identifying your spells as you cast them this way either, which is a major rules overhaul in its own way (and one that is several times more obnoxious for being a rule hidden in a FAQ that secretly alters the rules text that was explained in the Pathfinder Core Rulesbook, in order to nerf psychic spellcasting from Occult Adventures), but at least they can pretend it isn't. This must've passed for an "elegant" all-encompassing solution to these sorts of problems in the minds of the dimwits running the FAQs at paizo, avoiding needing to admit psychic spellcasting is poorly thought out, poorly playtested, and in need of an overhaul while resolving the issue of discreet psychic spell spam (but letting most of the problems with psychics remain unaddressed, because paizo).
However, no good GM in his or her right mind would ever want to enforce this FAQ, because the GM is the one who gets screwed the most by this, since Pathfinder is, in fact, full of monsters with SLAs that now can, under this FAQ, 100% get noticed and identified (which can be a bit of a problem), full of monsters that are obviously meant to use their SLAs subtly to affect a situation (which is completely fucked by the FAQ), and full of monsters that use illusion SLAs with disbelief saves (which are pretty much auto-fail on anyone who successfully passes a Spellcraft check to recognize what kind of illusion it is as it's being cast, which is now possible on SLAs, unlike before). And all you need to do to screw over monsters under a GM that enforces this FAQ is to just ask about those SLA manifestations and have a character with a good spellcraft skill modifier, zero cheese involved.
Most GMs aware of this ruling realize before long how much PF content this ridiculous retcon FAQ ruling would destroy if you were to actually apply this FAQ rule as written (because remember, Pathfinder's "elements of the game system [totally] work assuming that all spells have their own manifestations" like this), and thus don't enforce it, at the very least not as written, and prefer to houserule their own solutions to the above problem instead.
