The format for this file is very simple, versioned by filename and extension.
The data file follows a modified RFC822 format. Each line in the file is either blank or contains a variable assignment. Variable assignment lines are in the form:
During reading, variable names are forced to lowercase, and initial whitespace after the colon is ignored. Variable names may consist only of alphanumeric characters and underscores (i.e. they must match the regular expression /^[a-zA-Z_]+/).
All lines not separated by a blank line are grouped together. Each group must contain the variable "id", but may contain any other variables.
Groups are separated by one or more blank lines.
The first line in the data file must be a variable assignment line.
The recognized variables are: