There is no good answer to this. As I'm sure you found, if the old description is too long this is what you will get in the RevisionHistory:
DESCRIPTION changed [
value too long to display]
or from WS API when accessing revisions endpoint:
https://rally1.rallydev.com/slm/webservice/v2.0/revision?workspace=https://rally1.rallydev.com/slm/webservice/v2.0/workspace/1234&query=(User = your_user@your_domain.com)&fetch=true&start=1&pagesize=200&order=CreationDate DESC
DESCRIPTION changed [<br/>value too long to display]
Rally historic data is available from LookbackAPI. But per the Unavailable Fields section of the manual, big/rich text fields are not captured (Description, Notes, etc.)
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John Streeter
Customer Support Lead | ITSM & Rally Software
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Original Message:
Sent: 08-08-2019 02:28 PM
From: Stephen Olejnicak
Subject: Restoring a revision
We had a rather lengthy description in a feature (portfolio item) that we asked to have cleaned up by one of our SMs. Somehow they managed to miss a ton of requirements when breaking it into multiple portfolio items and decided to reuse the original PI for one of the breakout items. All the requirements are now lost and the revision history show not even 1/10th of the data.
How do we revert to a point in the revision history to restore the descripti
on to its state?