Is there a standard way of naming user-defined metadata tags in .flac files?

Question

Programs like metaflac let me add whatever tags I want:

% metaflac --set-tag="XXX=YYY" test.flac

% metaflac --show-tag="XXX" test.flac
XXX=YYY

I'd like to add metadata for personal use (where I bought it, what I paid, personal rating, etc.), but I don't want to simply say COST=$1.23, as the keyword "COST" might someday be added as a standard tag.

Is there an existing standard or convention for creating tag-names for user-defined metadata within the standard namespace?

Answer 1

The most efficient way to prevent name collision in the FLAC metadata seems to register a FLAC id as described here : https://www.xiph.org/flac/id.html

FLAC allows third-party applications to register an ID for use with FLAC APPLICATION metadata blocks.

An alternative might be to find an appropriate set of standardized metadata that includes the information you wish to store in the FLAC file. Some examples of such sets are Dublin Core and EBUCORE, although they may not be appropriate for your particular needs.