FLOSS (Fonemic Latin-One Spelling System) is a complex system of phonemic pronunciation that is used in dictionaries and other places to help with correct pronunciation of American words
The term "Floss spelling rules" may refer to one of two sets of rules.
The first Floss spelling rule is a rule of thumb used to help students understand when to double the letters f, l and s in words. According to this simple Floss spelling rule, these letters double at the end of a word when they follow a short vowel sound. Thus, words like huff, puff, stuff are 'f' floss words. Hills and pills are 'l' floss words, while grass and miss are 's' floss words.
If you're teaching spelling, here are some excellent resources for Floss spelling rules and other spelling rules:
The second Floss spelling rules involves a much more complicated system that uses phonetic symbols as a pronunciation guide. The FLOSS provides phonemic transcription of standard written American English.
When teaching phonetics, instructors may present Floss spelling rules to help students learn the basics of American English pronunciation. Note that Floss spelling rules can only be used with standard American English. Some substitutions can be made to accommodate British pronunciation, but in general Floss is meant for speakers of American English.
The current FLOSS spelling rules were derived from the latest edition of FLEWSY, the most common form of dictionary-type pronunciation symbols. FLOSS builds on FLEWSY with some subtle changes. Symbols used in FLEWSY, for example, that represent the Euro and other currencies have been changed to other symbols to avoid confusion.
FLOSS transcription requires some skill, but once learned, FLOSS serves students in good stead. Students who learn to read using a phonetically-based system can more easily pronounce unfamiliar words. They may also demonstrate stronger spelling skills since they can translate vowel sounds into standard written English.
Transcribing sounds from other languages into standard American English poses special challenges.
For a complete pronunciation chart of FLOSS notation, including examples of works 'translated' into FLOSS, visit WyrdPlay.org.