The abbreviation for idas should be used to start the second sentence. The colon in the second sentence is misused and unnecessary. The in-line series should use lowercase letters such as (a), (b), (c) rather than numbers.-no flip-flopping with abbreviations. According to apa style rules, once you have defined an abbreviation by writing out the full term and placing the abbreviation in parentheses, you must use the abbreviation thereafter. Apa allows the use of an abbreviation to start a sentence. the example shows a common misuse of a colon: many people are under the false assumption that a colon should be used to start a list.