Depends on the name. Most nicknames are just too light, informal, or trivial seeming to me on their own; but some grown-up sounding (to me) nicknames I like have full versions that don't appeal to me as much (Teresa and Andrew could become Tess and Drew). I think my default will be to plan on the most natural nick (if the name is naturally nickable), and give the full form on paper. A lot of my faves don't need nicks anyway.
What I'd do with your examples:
Lily - just the flower name stands well by itself. Lilian(a) I don't care for as much. If it were Lili, though, it'd need the Lilian.
Jacob / Jake, Samuel / Sam etc - I'd use the full on paper for sure. The nicks are just too familiar / informal for me
Jack - stands alone now, doesn't need to be John or Jackson anymore. In fact, it even seems a tad artificial to me to be John nn Jack.
Nataliya, Tatiyana, Frederik, Christian, Lucas and Gabriella: I'd give the full, use the nicks (or at least be willing to accept people using the natural nicks). I don't think the nicks stand alone well.
I guess it's just a subjective matter of appropriateness in formal contexts, like one's graduation or wedding announcement - to me you usually need the full version of a name; just not always.
- chazda
This message was edited 1/2/2006, 9:59 PM