Add External Standards VLR

[esilvia]

What is the issue about?

Other

Issue description

There is currently no standard methodology for recording which LDP or other non standards the LAS file is meant to conform to.

Some possible standards that matter:

1. LAS revision
2. LAS Domain Profile (topobathy v1, topobathy v2, transmission lines, etc)
3. ASPRS 2014
4. ASPRS 2023 v1, v2, etc
5. USGS LDP v____

Standardizing these with a lookup table would require constant maintenance. Perhaps the best solution would be for the VLR content to be a null-terminated array of URLs? Or maybe LAS wiki page names to err on the safe side?

[kjwaters]

I think an array that contained both a common (but not necessarily standardized) name and a URL would be good. Is there a common pattern for putting an array of strings in a VLR or EVLR?

[esilvia]

Discussed today in the LWG call (9/19/2024). The overriding sentiment is that we should keep the spec itself as minimal as possible. This probably belongs in the wiki: https://github.com/ASPRSorg/LAS/wiki/User-Contributed-VLRs