OK, that one was obviously too easy for you lot. Try this one...
My wife and kids will stay with my parents for the first six weeks or so, while I come back to the States to finish up the house and car sales, get the last minute storage items put away and generally tidy up all the loose ends (not to mention continue working until a bit closer to my anticipated UK start date of Oct 1). I believe I need to include a letter in the supporting documents from my parents, stating their ownership of their property, rooms enough for everyone, and willingness to accommodate them for as long as is required. Am I correct in this assumption? Do they need to include and supporting evidence with the letter (mortgage company statement, etc)?