“M81” is, in no way, the official or technically correct nomenclature for US Woodland Camouflage Pattern. I’ve dug in to this along with a bunch of other people who seriously know their shit about camo. It was adopted as the standard pattern of US forces in 1981 following the earlier ‘ERDL’ pattern, which is presumably where this term came from, but as I say it isn’t correct.
Closest proper name I’ve been able to find is literally just Woodland Camouflage Pattern, which is admittedly a lot to type every time so I can very much see the draw to calling it M81. A more proper abbreviation would be simply WCP, just like DPM or MTP, but if you said WCP nobody would know you meant Woodland. It’s a lot like the UCP/ACU debacle, ACU is used incorrectly so often that most people are actually more likely to conjure up the image of UCP if you just say ACU.
I’m pretty sure I’ll have made the aforementioned mistake in the past myself as I’d seen M81 used with such frequency and regularity in all corners of the internet that it seemed natural to assume it must be the proper name. However some time back I saw a comment on an entirely random page stating the opposite and eventually I got around to looking in to the matter a little more closely. Turned out the initial assumption had been wrong the whole time.
For those interested – for some time now I’ve been working (gradually) on a guide to all the different variants of legit Crye combats ever manufactured in Woodland and that will be appearing on the blog at some point in future.