A new documentation is available for Squash TM 2.0 and later versions, check it here
Xsquash4Jira plugin consists of 3 main functionalities :
An automatic synchronization plug-in, which enables Squash TM to automatically import and keep JIRA tickets up to date. These tickets will be imported to Requirements as synchronized requirements.
A reporting plug-in, which enables to display data in JIRA concerning the acceptance testing within Squash TM. This data will be displayed as personnalized fields to add to the JIRA tickets, including user stories.
A test plan creation plug-in, based on JIRA items, and which you can access under Test campaigns. You may for example create test plans from delivered versions of JIRA, from sprints, or from JQL requests.
Some functionalities are automatic and begin by themselves once the whole setup has been made.
Never will the plug-in erase any requirements which were synchronized in Squash TM, or any JIRA tickets during an automatic operation. If any tickets were to disappear from JIRA, then the corresponding requirements would remain in Squash TM and may need to be deleted per hand by the user if necessary.
Once the plug-in was setup correctly, the requirement base from JIRA will be automatically created and kept updated. After the first update, the plug-in creates the target directory ( See Create a synchronization ) and then populates it with the synchronized requirements from JIRA.
This part explains the organization of this asset under Requirements.
The main idea you should keep in mind is, the elements' hierarchy within the requirements tree explains how user stories, tasks and sub-tasks are related within JIRA.