[I like this one – quite unusual, and I think the first in the ‘Charity’ category – many thanks!]
Sender: National Churches Trust
Carrier: Royal Mail
Category: Charity
Nature of Contents: Charity begging letter [ed. Not my words!]
Envelope Description: White A5 window envelope, a “fat one”; Front: Franked Royal Mail “Postage Paid GB SOUTHALL376”; Back: If undelivered please return to: NCT, 7 Tufton Street, London, SW1P 3QB