I just learned that colons are only to be used after complete sentences:
"Use colons after complete sentences. Never use a colon after a sentence fragment. A quick and dirty way to decide whether a colon is acceptable is to test whether you can replace it with the word namely."
Source: Grammar Girl episode 241. Trivia: it sounds like the title of a Tom Lehrer song, but it was published on National Punctuation Day - "a celebration of punctuation which occurs each year on September 24th. Founded by Jeff Rubin in 2004, National Punctuation Day simply promotes the correct usage of punctuation."
1) Are the following three uses of colon appropriate? The first one does not seem to pass the namely test, the second does; but how can "which comprised two autonomous regions" be a complete sentence?
Changes in territorial configuration after World War I included:
Establishment of ...
Borders of ...
Bohemia, ...
The League of Nations granted France mandates over Syria and Lebanon and granted the United Kingdom mandates over Iraq and Palestine (which comprised two autonomous regions: Palestine and Transjordan).
Main article: Iron harvest
2) What about the following two forms?
Consider:
<some quote>
Trivia: it sounds like ...
Source: <some reference>
