Creating an experimental namespace for new functions

[situx]

For functions which have not been standardized in GeoSPARQL, but which may be standardization candidates in a future version,
I would like to propose the following namespace:

http://www.opengis.net/ont/geosparql/ext/

Do you agree or do you have other suggestions?

We can use this namespace in experimental implementations, which will then eventually update functions which have been standardized to the official namespace.

[afs]

The community experience with content type names and HTTP headers starting "x-" might be useful here.
The "x-" becomes effectively permanent (e.g. application/x-www-form-urlencoded).

https://developer.mozilla.org/en-US/docs/Web/HTTP/Reference/Headers
https://datatracker.ietf.org/doc/html/rfc6648

If it is quite likely a function name will at some point become part of the standard, an alternative is to allocate the name in the intended namespace and clearly label it as "experimental". It is less painful to withdraw experimental names that don't make it to standard.