So does ISO900 1:2008: 2008 standard 4.2.3 talk about specific methods of document control?

Of course not. So, you did not violate the requirements of QMS standard.

So, are there any rules? You are a procedural document, not a state secret material, so you care about the enterprise's own regulations, so you don't violate this criterion.

That depends on your file control program. Does it provide for such activities? If it is clearly stipulated that signatures cannot be printed, it will not work. If there is no regulation, this can also be done.

Suggestion: If you think this document control method is suitable for your company's document control, please put it into the document control program. This also has a procedural regulation and constraint on your file control method, which is more suitable for file management.

Personal advice from a QMS auditor, hehe.