I was curious - can a child workflow only be called by another workflow or can it also be used as a standalone workflow?
In Crm 4.0, if you mark a workflow as a Child Workflow it can be called from within other workflow as a sub process that's run asynchronously. It can also be ran as a standalone workflow in it's own right.
The tickbox is additive in that it just means the workflow can also be ran as a child process.