Ultimately, it's the goal of TGW to know everything. But until then, the best way for it to grow in usefulness is for articles to get written in response to searches you folks make.
Yes, this is a work in progress.
Articles Written or Updated in response to these questions
I do tend to give quick responses to a lot of the questions in here. However, some questions come up often enough (or the area is murky enough) that they warrant new articles or updates to existing ones.
AboutOpticMounts, which covers all the standards I'm personally aware of, plus a few popular improvisations.
RecModsSu16, which addresses popular modifications for the SU-16.
rimfire mag california legal: Unless the magazine is a .22 tubular feeding device, 22LR magazines are limited to 10 rounds like all other magazines. See LegalCaliforniaMagazines.
scatch maroo: One of the early significant names in the off-list movement. You can read a bit about him in HistoryOLL.
nut mag legal high: You undoubtedly mean a Beta-C magazine. Outside of California, they're legal in most states. Within California, see LegalCaliforniaMagazines.
fs2000 rimfire: Were there a rimfire version of the FS-2000, it would be California legal. However, at present I'm unaware of any rimfire conversion. For the record, AR-15 Ceiner conversions wouldn't fit.
california legal ar 15 upper receivers: The only illegal AR-15 uppers would be 50 BMG uppers, if you don't possess a lower registered as either an assault weapon or as a 50 BMG rifle. Lowers, on the other hand... well, LegalCalifornia has a lot of info for that. Note that the upper itself wouldn't be illegal to possess - only if it's attached to an AR-15 outside of the prior categories, thus forming a complete 50 BMG rifle.
norinco ak 47: Norinco is a Chinese manufacturing company. Their AK-47's were fairly well spoken of. The most prolific Norinco AK is the MAK-90, which of course is a prohibited rifle in California.
dpms lr 308 oll: Unfortunately, all DPMS receivers are listed, so (until 2010) there were no OLL DPMS rifles (other than a very few ones produced in the early days). The list says "DPMS Panther (all)", and so pre-2010 all DPMS receivers said "panther" somewhere on them. Additionally, see Ref308ARs for a relatively complete 308 AR compatibility chart.
yugo m70ab1 side folder: The M70AB1 is a fixed stock rifle, and I am not aware of any side-folding stocks for it. It doesn't use a standard AKM rear trunion, so it will not accomodate the large variety of side-folding stocks available for those rifles.
("222 rem mag" or "222 remington magnum" or "222 mag" or "222 rem magnum") and "semi automatic": This round is very similar to the standard 223 Remington case. If you own a rifle chambered in this, I wish you the best of luck in feeding it. If you're thinking of buying one, you should look at 223/5.56mm instead. Ballistically, the 223 will do everything that 222 will do, and it's widely supported.
m-950 handgun: The M950 is also known as the "Calico", which is a helical-magazine-fed rifle from Calico Light Weapons Systems.
nds/3 receiver for ak 74: No, the magwell dimensions are a bit off. You're better off using an actual AK-74 receiver.
u15 rifle stock: The U-15 stock is a California-compliance AR-15 stock. It uses the pistol grip attachment point, and is patterned after the stock of an M1A. Because the U-15 is not a pistol grip, its use does not prohibit detachable magazines on rifles.
c&r transfer non-licensee: A C&R holder may transfer a C&R firearm from their collection, to a non-license-holder, provided that it's legal by state law and that they have no reason to believe that the non-licensee is prohibited from owning firearms. Bear in mind that the C&R licensee has absolute discretion in choosing not to perform a transfer. There is absolutely no law which says you must transfer a firearm to someone who gives you the slightest wrong impression. So, if in doubt, don't transfer. Incidentally, in California a C&R holder may transfer only long arms more than 50 years old; no handguns regardless of age. Antiques, of course, are exempt.