From Pittsburgh Streets
The {{letter}} template is used to make a citation for a letter. Sources that use the {{letter}} template are added to Category:Letter sources.

Full syntax

Template with all parameters Parameter Description
first Author's first name.
last Author's last name, or the whole name of the uthor when that author has a single name (such as an organization).
title Title of the letter. This should be in sentence case. If no title is provided, the citation will say "untitled letter."
date Date of the letter.
note A note to be appended to the end of the citation.
is-subref Set this parameter to true when citing this letter inside the definition of another source in the "Source" namespace. This changes some punctuation and suppresses the categorization of the source in Category:Letter sources.
source-name The page name of this source (in the "Source" namespace). This is used to provide a link to the source page.

Usage examples

 |note=Printed in {{news
                   |first=Frank C.
                   |title=Pittsburgh day by day
                   |paper=Pittsburgh Press
J. C. Andrews. Untitled letter. Printed in Frank C. Harper, "Pittsburgh day by day," Pittsburgh Press, Jan. 8, 1929, p. 2 (Newspapers.com 146342285). [view source]andrews