According to the valve wiki, the trusted_source option is only available for mods on the Source SDK Base 2007 or later. This mod is on 2006.
I have a few more questions.
What happens if a directory is not even listed in the whitelist? Will it allow or disallow anything in that directory to be changed?
Also, what happens if I want to make an entire directory filled with thousands of files to allowed, but then want to make a few of those files within the same directory disallowed?
For example,
materials\... allow_from_disk
materials\test1 allow_from_disk+check_crc
Since I already specified to allow from disk on the whole contents of the materials folder, would the setting below that for materials\test1 files overwrite the setting above it or would it still allow it because it's already specified as allow_from_disk in the first line?
And can the *.* part I can put at the end of a directory name also be used on file names within that directory? For example, materials\effects\cloak*.* (all the cloak files are in the effects directory.)