Older versions of a CDT - are they deleted when there are no references to them?

If a CDT has no longer any references, does Appian have any policy so that the old CDT version is deleted after some fixed interval?

I guess, New version replaces old version. So you cannot find the old version. And where ever you see ^ followed by a number, just click on that a new empty CDT will appear with ^ followed by a number.

When a data type is deleted, it is retained in the system so that objects can continue to function correctly even if referenced data types are deleted. Deleted types, however, will no longer appear in the Appian Designer or as choices in type pickers.

Upon deleting a data type, references to that data type will have a version number appended in the form of a caret (^) + version number. For example: myCDT^1, myCDT^2.

Objects that use a deleted data type can be exported and on import, will attempt to reference the most recent version of the data type. If the most recent version of the data type is deleted, import of the dependent object will still succeed. If no data type exists on the destination environment, import of the dependent object will fail.

please ignore my first comment and second comment data was found in forum.

@kondetiv, the new version does not replace the old version. You can reference the old version even after the new version of CDT is created.
The old version exists.
My question is that - is it ever possible that the older version of the CDT be deleted permanently after some long duration - when the old version is no longer referenced anywhere

Chetan, all version of the cdt are stored in Appian Primary Database. The table which is used to store this information is DT_MODEL. Database cleanup is not happening as of now.

Thank you Summeet for the reply. It means even if a old version is not used anywhere, it will still remain in the environment

CDT's will still exist in the environment even if no objects references it.

Is there any way to download the older version of the cdt?

Is there any way to access these older versions?