Restricted Words are words that are restricted for a purpose.
For instance Investment can be used for a limited company with EG Chioma Egwu Investment Limited.
But when it comes to a business name, the word investment is restricted. You can only obtain consent from the RG, before the word is used.
These days the word global, International is a restricted word for foundation and association or clubs or societies. CAC requires you just whether it is affiliated to a global foundation or association.
The word Africa was before now not a question, but if the word is used in a name, CAC will ask for justification.
Prohibited words are words, that can never be used. Words like Chamber of commerce can't be used. Words that will breach national security or deceive the general public or against natural justice, can't be used.
Also note that
Limited companies are
Private company limited by Shares which is the most common to be registered ends with LTD
Private Company limited by guarantee LTD/GTE
Public Limited Company PLC
Unlimited Company UNLTD
Check previous posts on other CAC stuffs.