Use of terms: Technical or Layman

Recently, I stumbled upon a situation where I need to create a form with fields that are somewhat unpopular.

For example, I ask for users' post-nominal letters. Now this term is really not so comprehensive because most people (at least most my users) do not understand what that is.

Some alternatives that I can think of:

• Rephrase it into something like "Awarded Designations" or "Professional Qualifications" (but it doesn't really cover the whole meaning of "Post-nominal Letters").
• Use descriptions to explain the term (but long descriptions is not nice to the layout).
• Use placeholder to show examples (but it can't cover too many use cases).
• Use an information icon where users can click to expand a toolkit explanation (but there's no guarantee users will click it).
• All of above (but it makes a simple form seems very complicated).

So in cases like these, should I stick to the correct use of term, or should I choose another term that is easily understandable to my users, or is there anything else that I can try?