This dictionary lists some vocabulary that might not be common, or that has specific meaning within the project.
Similar to Red Hat’s process of backporting, the IUS Community Project also performs back-up-porting. This is the process of taking a backport [i.e. a patch] from a Red Hat update, and then up-porting it to a newer version of the same package in IUS.
Often times back-up-porting does not apply cleanly usually because the diff patches were against a different version of the source. This all depends on how far you’ve diverged from the Red Hat version... as well as if the file(s) in question have changed since then.
It should be noted that just because Red Hat backports something, it doesn’t mean IUS packages need that update. To be sure you can verify the CVE or similar security tracking number to determine if it applies the IUS version of the source. Also, back-up-ported patches are generally only required and applied during the interim before the next upstream source release. Almost always, these patches are applied upstream and need to be removed during the next source update (only if it’s been previously applied).