Hi and thank you again for your informative reply.
Can you suggest some resources to research these restrictions?
You should very soon start talking to certification bodies. They can help you with most if not all of your questions, and they should have no trouble providing you with their guidance document on the use of certification marks.
For your benefit, I'll outline a few in what is a typical set of rules.
Typically, certification marks are used on the web site, business cards, letterhead, stationary, catalogs, advertising, and other literature. Using the marks is completely optional. You don't need to use them at all, or you can use them on any or all of the typical things I listed.
Certification marks include the use of "ISO 9001 Certified" and closely related wording. It also includes the seals that belong to your certification body, and the seals that belong to their accreditation bodies.
Certification marks may not be used on the product, product packaging, or in a manner that would indicate that the product is certified. Certification applies to your quality management system and not to the product.
Certification marks may not be used in a manner that makes it look like more is certified than what is in the scope of certification. That includes facilities are are not part of the certification. It also includes activities that are not part of the scope of certification. For example, if you have six locations, and only one is certified you must not use the marks in a manner that makes it appear that any of the other five are included in the certification.
If your scope of certification includes manufacture of car parts, and the manufacture of buggy whips is not included in the scope, then you cannot claim that your certification covers the management system that manufactures buggy whips.
Generally speaking, you can use the certification body seal by itself. If you use accreditation body seals, they must only be the ones on your certificate, and they need to be used with the certification body seal.
There are details about the size, shape, and colors used on the seals, and that detail is provided on the guidance document.
Auditors are instructed to check on the use of the certification marks on every audit.