Inconsistency in attachment ID

Hi,
We are facing a little inconsistency concerning the attachment id.

In the REST API the attachment IDs have the form “att12345678”.
(i.e. ‘/rest/api/content/{content_id}/child/attachment’)

In the Confluence Server JAVA API the attachment IDs have the form “12345678”.
(i.e. attachment.getContentId())

Removing/Adding the “att” prefix is an obvious workaround, but I wonder if there is another way to solve this inconsistency (another API?) without assuming any naming convention that could be broken in the future.