The preferred and most acceptable way to use abbreviations, or acronyms, is to use the abbreviation followed by the explanation in parentheses, as follows:
Yamaha keyboards are the best keyboards on the planet, IMO (In My Opinion).
That only needs to be referenced like this in the first usage in the communication, because thereafter it is understood.
In business communications I sometimes wrote something like this, as follows:
Yamaha keyboards are the best keyboards on the planet, in my opinion, hereinafter referred to as IMO.
Either one of these methods communicates the meaning if the abbreviation or acronym to the reader.
BTW (By The Way), this has been discussed many times on the forum in the past.