Semicolons in a List

  The most common use of the semicolon is to join clauses containing similar ideas. Another use of the semicolon is to clarify lists. If a list contains commas within the elements of the list, those commas remain, and the elements are separated by semicolons. The first red mark shows where a comma introducing a verbal phrase should be. The remaining three marks denote where a semicolon should be. 

  One writing website (http://writing.wisc.edu/Handbook/Semicolons.html) explains it like this:

• Use a semicolon between items in a list or series if any of the items contain commas. 

  There are basically two ways to write: with a pen or pencil, which is inexpensive and easily accessible; or by computer and printer, which is more expensive but quick and neat.