.Diploma is not only awarded in Nigeria polytechnics, some universities and college of education are also issuing diploma certificate and these certificate is different from each other and their acceptability differs.
Polytechnic awards OND,which can be use for 3 different things.
1) to secure a job
2) for HND programme
3) for direct entry
It generally r acceptable in all university and Polytechnic and many have used thier diploma to secure job.
However the same cannot be said about university and college of education diploma.
1) University diploma is not generally acceptable in the job market and you may not be able to use it for direct entry in another university.
2)It will not be acceptable for HND
In any Polytechnic because university diploma is not recognised
3)However it can be used to secure admission into the same university it was obtained.
College diploma is closely related to that of university diploma and it not well accepted like the polytechnic national diploma however some university consider it for direct entry.
You will have to check the university admission requirements to ascertain the acceptability