Allowed characters for Descriptor Values

[DiVe]

DRAFT

In the specification of the ISO MME (V1.x) several descriptor values are given the attribute:
"alphanumeric"

Indeed this is not very specific. You will find (https://en.wiktionary.org/wiki/alphanumeric):

2023-10-17 12_20_44-alphanumeric - Wiktionary, the free dictionary – Mozilla Firefox.png (13.24 KiB) Viewed 2077 times

Based on the encoding for the descriptor files of ISO 8859-1 this will enable a wide range of characters that might be used.

2023-10-17 12_29_21 ISO8859-1_encoding.png (145.98 KiB) Viewed 2077 times

Indeed some characters that are difficult to distinguish should be ommited.
In ISO MME V2.x the definition of the descriptor values is available in more categories:
- „string“
- „reference“
- „filereference“

And for string each character from the ISO 8859-1 is allowed:

2023-10-04 13_31_23-ISO_TS13499_RED_A_V2.1_Rev_20200218_ - PDF-XChange Editor.png (18.71 KiB) Viewed 2077 times

It would be helpful to provide a specific subset that is allowed or at least recommended for the exchange.