FYI is a common abbreviation of For Your Information. On the internet, FYIs are a subset of the RFC series. The following description is taken from FYI 1, the FYI on FYIs:
- The FYI series of notes is designed to provide Internet users with a
- central repository of information about any topics which relate to
- the Internet. FYIs topics may range from historical memos on "Why it
- was was done this way" to answers to commonly asked operational
- questions.