There were not reactions on roundup-user to this,
but as I think it is important I repeat it as a
wish:

I'd like to know if there is a solution to a problem I
just
encountered: assume you have a multilink property in a
class, and you
want to modify this property by email. It is possible
to say
[<propertyname>=<list of designators/keys>], but this
completely
overrides the previous values of this properties.

Although consistent, this is still pretty inconvenient,
because
I have to take special care to copy all of the old
values when
adding a new one. This might be impossible for users
without
access to the current database (as we have here).

Would it be possible to support something like
[<propertyname>=<[+-]designator/key>+] that adds (+) or
removes (-) just the given objects from the multilink
list?