Our HN awards have had something called "local options" for a long time. This allows centres to effectively add any units they like to the awards (although the number of credits is capped). These were originally conceived to help centres customise the awards to their specific local circumstances. For example, a particular college with a large local employer may have a very good reason to add an "unusual" unit to their specific HN award.
Computing is now one of the few subject areas to continue to offer local options. Their use has declined for various reasons including the adminstrative overhead of constantly updating frameworks, and it sometimes being used to provide credit for units that really don't fit the rationale of the awards at all.
I will clarify the rationale and procedure for using local options in my forthcoming update letter, which should be sent to centres in the next few weeks. We will continue to offer it but tighten the procedure to ensure that the awards continue to meet the purposes for which they were designed.