Using other mod items

Calling another mod blocks item, I know someone making a luckblock also in MCreator, they really would like to call some of my items
how would we let this happen, would they go about doing this?

No they can't have my mod files since there all custom and soon as they import them would brake the items and blocks, and I be nice
to know this so when others create lucky blocks so it can use items for other mods, makes it more useful them.