That sounds like the Audit History of an Asset to me. So, the Audit History is a log of all changes to the asset... be it done manually or some automated way. When looking at an Asset, on the upper right area by the SAVE/NEW buttons, there will be an Audit History link. take a look at that. It doesnt look like SDM's Comment Log, but it is a view of all changes to the asset, who did the change, what was changed, etc.