It would be interesting to be able to sanitize string fields by using a mask.
For instance, if we want to transform a full URL to a hostname:

http://some.host.name:8080/some/web/path?and=some&query=string

to a more privacy-aware truncated url like:

http://some.host.name:8080

Another example could be an identifier composed of:

<namespace>:<element>:<detail>

This one could be masked to i.e. not contain the detail:

<namespace>:<element>

In addition to that, it could solve T279952.