Gets a list of available rule formats. Use these version strings available in the response's ruleFormats.items array to control the set of behaviors and criteria you invoke within an include's rules to apply to edge content. If you'd like to use the latest rule format and take advantage of the new or updated features Akamai releases routinely, see Dynamic rule updates for more details. If you prefer to use a dated rule format version, see the instructions for freezing a rule tree or updating to a new rule format. To validate a rule tree to the requirements of a specific rule format, see Get a rule format's schema.