single standard; single base
Used in contexts like pricing, evaluation, or systems where only one criterion or base is applied, rather than multiple tiers.
This store uses a single-price system for all products.
single-feature show
Refers to a performance or event centered on a single act or feature, such as a one-man show or a film program with only one main feature.
Tonight's screening is a single-feature show, just the feature-length documentary.
Compound of 一本 (ippon, 'one long thing') + 立て (date, 'standing' or 'establishing'). The exact derivation is uncertain, but it likely refers to setting up a single standard or a single featured item.