From GEAR Software Knowledgebase
A file system specification created for CD-ROM. It was originaly known as the High Sierra format and was adopted by the International Organization for Standardizations in order to create a universal filing system, so data can be shared by multiple different OS.
True ISO format has 3 levels.
All levels use only uppercase letters, numerals or underscores. Individually these levels have some variance though which consists of:
- Level 1 : File names are restricted to eight characters with a three-character extension, upper case letters, numbers and underscore; maximum depth of directories is eight.
- Level 2 : File names may be up to 31 characters.
- Level 3 : Files allowed to be fragmented (mainly to allow packet writing, or incremental CD recording).
Although many of GEAR's ISO option do not specifically conform to the strict ISO 9660 standard it is within all acceptable realms of ISO and run without error on most platforms.
GEAR does allow the strict level 1 ISO 9660 formatting, and uses it specifically without choice, concerning the ISO portion of a DVD Video project (Conforming to DVD Spec).