For a number of years, Houghton Mifflin, now owned by Harper Collins, sent a selection of books that they have recently published either under their name or one of their imprints. Each shipment was diverse, covering a wide variety of fiction and non-fiction topics.
Before these items start circulating, a note is placed inside each one so that the reader knows that that particular book is available to them through the generosity of Houghton Mifflin.
This note shows the year and general time period it was received ("Winter" could denote that an item was received early or late in the given year)