I propose that the dos and ddos tags are replaced with denial-of-service, and synonyms are set up appropriately. This provides absolute clarity, rather than an ambiguous acronym. The new tag should also encompass non-flood attacks, such as exploiting poor incorrect password blocking systems.
Users should be encouraged to combine this tag with other tags for specific types of attacks, e.g. syn-flood.
The problem is that the tag names are always lowercase, and there are other things that might come under the "DOS" acronym, e.g. Distributed Operating System, Distributed Object System, Disk Operating System, Data Over Signalling, etc.
I also don't think we need a separate tag specifically for distributed attacks, since the distinction is minimal and most ddos questions also get tagged as dos.
Thoughts?