An include spec is a rule that indicates to OrgFlow whether a particular metadata package, namespace, type, or item should be processed by OrgFlow. Include spec rules can be combined to create a rich and powerful filtering syntax.
See Include Specs Syntax for more information on the syntax of include specs.
For Stack Based Commands, your .orgflowinclude File contains your include specs. Org Based Commands that require include specs will have an argument that allows you to pass a delimited string of include specs (see the reference page for each command for more information).