Documentation of *.xml.fdm_material naming valid characters

[gbarbehenn]

Cura Version

5.9.0

Operating System

Windows 10 Home 64b

Printer

Elegoo Neptune 3 Pro

Reproduction steps

Add a new filament, and use the quality and intent files from another media as a starting point for new profiles.
Added PLA+ filament by editing "generic_tough_pla.xml.fdm_material" to "generic_pla+_175.xml.fdm_material", and imported it into materials. Succesfully.
This material was added to %APPDATA%...5.9\Resources\Materials as "generic_pla+_175.xml.fdm_material". However copying the PLA (and editing) to PLA+, in either the cura\resources or corresponding %APPDATA%...Resources directories still results in "unsupported".

Actual results

The 'new' materials quality or intent settings are "not supported"

Expected results

The 'new' materials quality or intent settings show up when the 'new' material is chosen, albeit still the settings of source material. I've done this with several materials (ABS -> Nylon, PLA->PVA), and the only differences I can see are that this new material was imported and so resident in the %appadata% labyrinth, and that the character "+" is used in the filament name. I tried all combinations of %appdata%, and Cura directory, sub-directories, and so have convinced myself that is the "+" (?). But, I don't see any documentation on what are acceptable characters for naming files (or directories)?
Since the file names use "_" instead of " ", and there are a variety of other UI issues, this appears to be compiled on Linux. I don't use Linux, on purpose, so I'm not familiar with character limitations, this should be documented at https://github.com/Ultimaker/Cura/wiki/Profiles-&-Settings. Like front and center.
Also, as an aside, the file type restrictions for attaching files, below, should also be documented in the "Paste, drop or click to add files" instructions, since adding a file is required. "Only XXX file types are allowed" would be much better than saying "File type XXX is not allowed"!

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generic_pla+_175.xml.zip