Prepositions - Prepositions of Reference

used to indicate conformity with a standard or expectation

used at the beginning of a business letter, etc. to indicate the subject of the letter, or an email that is a reply to a received one

in conformity with or following a particular standard, rule, or guideline

in regard to what someone has said or written

used to indicate a connection or reference to something else

used to introduce a comment, observation, or topic that is relevant, appropriate, or timely

used to show compliance with a specific rule, guideline, or standard

because of a particular situation or information

referring to or concerning a particular topic, subject, or context

used to indicate that something is being mentioned or discussed in relation to a particular subject, source, or context

following a specific law, regulation, or requirement

as a reaction or answer to something

used to indicate a relationship or association between two or more things