Current standards allow the use of a colon or semicolon in the following sentences. The sentences show a connection or shared theme between two clauses, or use the second clause to reiterate or amplify the idea in the first clause:

Remember to start the phrase following a colon or semicolon with a lowercase letter.

Try to limit your use of colons and semicolons. Separate sentences with a period if possible.

A colon is generally used before a list or series:

But not if the list is a complement or object of an element in the sentence:

Use a colon after "as follows" and "the following" if the related list comes immediately after:

Use a colon to introduce a bullet list (or dash, or icon/symbol of your choice):

Use a semicolon to separate items in a series if the items contain commas:

Use a semicolon before a conjunctive adverb (however, therefore, otherwise, namely, for example, etc.):