I suspect people making sectionals don't know everything on it, either. Otherwise, it would all be in the legend. Try to find the "special military activity" (gray cross-hatch -- an example is on the Los Angeles Sectional south and west of Edwards) areas there.
During my oral, my DPE pointed out a 50% gray line 1 mile south of the Squaw Valley VOR (west of Lake Tahoe) on the San Francisco Sectional, and asked me what it was. It's not in the legend. I swear I wanted to punch him for that. The answer is much more obvious on skyvector than it is on a paper sectional like I had.