I don't know how to edit a multivalued field

[prescom]

I'm dubious about my understanding about ergonomics of the program called Configuration for the Alcatel OmniPCX Enterprise.
I just cannot edit a multivalued field.
Example: In the "Associated Phones" section there is a "Supervisor Phone" entry to which one can associate several numbers.
And although I double-click as a damned on the field containing the values ​​(data that the person I replaced had already filled) or which will contain them, nothing happens.
I can type anything on the keyboard, no more reaction or text field change.
And in the contextual menu, there is a sub-menu "Edit" which in turn contains "Copy", "Paste", "Delete lines / sheet" and "Set by default" actions. But apart from the fact that there is no "Edit" action (for example), none of the available actions seems to produce a perceptible change.
It is hopeless. For a little, I'd come to believe I'm an idiot. (It's not excluded but I keep a little hope that not.)

I should like to point out that I have read a number of documents that I have found and have seen no explanation on this subject anywhere.

Thank you in advance if you can help me or suggest documentation,

Yannick

[ltatge]

Some fields in 4760 are read-only. Parameters are elsewhere configured and only shown for info.
Search for system-docs, read a lot and test it out. Or take a training at ALE or ask a ALE-Business Partner to help you.
Difficult without knowledge...

Regards