REVLOC, stands for types of syllables. These syllables are then classified by the corresponding letter from the REVLOC system. Once classified (or maybe labeled is a better term), the word can be broken down and pronounced based on the rules associated with each syllable type.
The word “REVLOC” is what it is because that is the order in which each syllable type should be considered in pronunciation. For example, the word “war” might look like it is a closed syllable, however, the “ar” in this word make it an R-controlled syllable. R comes before the C in the word REVLOC, so that is how we know that the R-controlled is the rule to follow rather than Closed.