Interesting behavior. We've had this behavior with status and progress since v12.1. We are now on 13.2. There has been no change, as far as i know. Here is some text on what I know. I hope it makes sense...
The Project Status field uses the system-restricted lookup 'Investment Object State'. The 'Investment Object State' Lookup has six values defined:
'Approved', 'Cancelled', 'On Hold', 'Rejected', 'Resumed', 'Unapproved'.
In Clarity 8.x, the 'Investment Object State' lookup has 3 additional lookup values defined: 'Converted', 'Incomplete', and 'Submitted for Approval'. These lookup values are used for the Idea Object and only appear on Idea instance records.
There is logic built into Clarity that controls which values are available.
This logic is based on the values in the Status field, the Progress Field, and the date fields in the Project Investment.
When the project is created, it is given a default status of 'Unapproved'.
If a project is Unapproved, the end-user can change it to 'Approved' or 'Rejected'.
If a project is 'Approved' and has a Progress of 'Not Started', then the status can only be changed back to 'Unapproved' or 'Rejected'.
If a project, without a simple budget, is 'Approved' and has a Progress of 'Started', then the status can only be changed back to 'Unapproved' or to 'Canceled'.
If a project is 'Cancelled' and has a Progress of 'Started', then the status can only be changed back to 'Approved' or to 'Resumed'.
A project, with a simple budget, can only be changed to 'On Hold' if it has a Progress of 'Started' and the current date falls between the Budgeted Cost Start date and the Budgeted Cost Finish date. As of Clarity 8.0, "On Hold" is not available unless the project status is approved. You will need to change the status to "approved" prior to selecting "On Hold".
My question revolves around the concept of the Simple vs. Regular budget. That seems to change the states that are available. All I want is some documentation that informs me of how this behaves in the system. Are there other affects, for example, when I place a project on hold?