Homologia (Epistolary Exchange)
A homologia is an agreement or acknowledgement with some form of ὁμολογῶ as its main verb. It can be drawn up by the scribe in an objective or subjective formulation, and can therefore be found under more than one category. This description concerns the subjective homologia as a variation of a [cheirographon]. Another variation can be found under [homologia (Transmission of Information)]. Objectively styled homologiai may be found under [syngraphe ].
The content of documents drawn up as homologiai (Epistolary Exchange) include loans of grain [3747 116 BCE, Kerkeosiris], money [15838 197 CE, Hermopolis], or both [23600 252 CE, Herakleopolite nome]; also declarations of surety [12558 20 BCE, Arsinoite nome; 15915 257-258 CE, Aphroditopolite nome], animal sales [20176 44 CE, Arsinoite nome; 26538 II CE, Soknopaiou Nesos], or transportation [10556 131 CE, Theadelphia, transportation of dung to a vineyard; 16892 264 CE, Oxyrhynchus, return of a boat; 11678 118 CE, Arsinoite nome, transport camels for grain]. Examples of such documents are found from the II BCE to III CE.
The structure is that of a cheirographon but without χαίρειν after the opening address, e.g. [20176; 12558]. Further information such as the status and origin of the parties can also be added [3647 119 BCE, Kerkeosiris]. An agreement to substitute for two tax collectors refers to itself as a cheirographon [10875 l.4, 161 CE, Theadelphia].
Another opening is of a kind more associated with an [official letter ], with the addressee placed first.
This inverted formula perhaps indicates a hierarchical relationship between sender and addressee, as in some official letters. The opening address also contains status and origin information, e.g.  and sometimes includes an intermediary .
The homologia is written invariably in pagina format with the writing along horizontal fibres. The dimensions of the few complete documents extant range from H.28 x W.8cm  to H.22 x W.11.1cm ; one example is relatively narrow [16892, H.23.6 x W.6.2cm].
Some scribes arrange the text in a single block with no distinctions between the sections [10875; 20176]. Others have a space between the main text and the date [3747; 15915]. There are also examples where the date is indented . Another displays an enlarged initial letter . There is often a large bottom margin [10875 (5.9cm); 20176 (11cm)].