/summon help 4

I think the "Lore" tag is what you're looking for. It's nested inside the "display" tag, and is a list. Every item in the list is a new line. Example:/give @a diamond_sword 1 0 {display:{Lore:["Line 1","Line 2","Line 3"]}}

That also brings up another question. Are you using /summon to actually summon an item on the ground, or are you just giving it to a player like I did above? If you are using summon, then I believe the data I put above has to be further nested inside the "tag:{}" tag (Assuming I'm remembering it right).

EDIT Ok, you figuring it out yourself works too

nevermind it is the display/lore data tag