Assignment of private use language subtags

[Gordon P. Hemsley]

Hello all,

I was just informed about the existence of this mapping of private use 
language subtags to languages, maintained by LINGUIST List and used by 
MultiTree:

https://en.wikipedia.org/wiki/List_of_ISO_639-3_language_codes_reserved_for_local_use

Does anyone have any opinions as to the importance of this list, and how 
much others should be concerned about clashing with these assignments on 
the wire? (I know there are similar lists maintained for the Unicode 
private use area that have some importance for unencoded script users.)

How safe is it to ignore these assignments?

Regards,
Gordon

-- 
Gordon P. Hemsley
me at gphemsley.org
http://gphemsley.org/