Think of this from a risk perspective: how does your organization need to control your documents to ensure that the appropriate people have access to them, prevent/minimize risk of people using outdated documents, ensure people can find the right documents when they need to, and documents are retained for as long as they are required, etc.?
Document ID numbers can be helpful in many cases, but aren't required. You might find it easy to just create and maintain a list of documents, with incrementing ID# like QMS-12345, QMS-12346, etc. Or maybe use category codes+numbers, such as MFG-12345, CAL-34567, MGT-54321, etc. to group the docs and give give people a sense of what the doc applies to. If you use MS Word or similar, create a template document that has a table in the header, with entries for title, doc ID#, revision, etc. The more you can standardize, the easier it will be.
But note that document control also applies to things like customer-supplied documents (how do you control them?, where are they stored? how is access controlled? how long must you keep them? how do you dispose of them?), and "documents" in an ERP system, like sales orders, purchase orders, etc. How are those identified and controlled?
So, document control is a pretty broad topic, covering quite a bit. The standard prompts us to have to take a risk-based approach based on our specific organization and needs. The needs of a small, single-site company is much different from a multinational conglomerate, and the document controls for a defense contractor is much different for an online store selling bird feeders, but the standard can be applied to all of them.
