help desired with interaction with inetd.conf

[Shaleh <shaleh@livenet.net>]

Hi all.  I am packaging an identd server.  I would like it to run from
inetd.conf instead of identd.  I can not simply divert the identd binary
because oidentd supports additional command line args.

So I forsee that my postinst should remove the current identd and add itself. 
The postrm should remove oidentd and put identd back.

My question is: how do I correctly run update-inetd?  I can not see an easy way
to test that the identd line was added by me and not by someone else. 
Otherwise every time the package is updated it will try an remove identd and
replace it again.

If all this is documented somewhere, please let me know.  I understand the
basics of "add this to inetd" or "disable this", but switching foo out for bar
I am not seeing.