Codetta (Italian for “little tail”, the diminutive form) has a similar purpose to the coda, but on a smaller scale, concluding a section of a work instead of the work as a whole. A typical codetta concludes the exposition and recapitulation sections of a work in sonata form, following the second (modulated) theme, or the closing theme (if there is one). Thus, in the exposition, it usually appears in the secondary key, but, in the recapitulation, in the primary key. The codetta ordinarily closes with a perfect cadence in the appropriate key, confirming the tonality. If the exposition is repeated, the codetta is also, but sometimes it has its ending slightly changed, depending on whether it leads back to the exposition or into the development sections.

https://en.wikipedia.org/wiki/Coda_(music)