Different subjects should keep different names
A return reports information for a period; a notice communicates an authority’s issue or instruction. A payment agreement is a particular arrangement, and a request for penalty relief raises another subject. An offer in compromise also has its own requirements. Use current IRS resources to understand the term actually relevant to your question rather than treating tax relief as one uniform process.
Ask what the term would mean in your file
For any suggested option, identify the account or period involved, the records required, and what decision would still belong to the authority. A proposed request is not an accepted outcome, and a professional service description is not the same as the official process. Keep those distinctions in your notes so a conversation can explain the task behind the label. This page provides general language orientation; it does not select a process for a reader, interpret a disputed legal issue, or establish eligibility for any tax option.