The present article investigates how the critical, though ill-understood notion of “social meaning” in Post-classical Greek can be captured. The author reviews the relevant literature, including certain cognitive linguistics principles and adopts the framework of Systemic Functional Linguistics (SFL). Within this framework, he analyzes five sample texts –letters- form the fourth-century Theophanes archive. The paper takes into consideration the differentiation between “direct indexicality”, as established by referential indexes, and “indirect indexicality”, as realized by non-referential indexes, a differentiation proposed by Silverstein (1976) and Ochs (1992). In particular, the goals of this research are a) to distinct the linguistic structures which function as referential and non-referential indexes, b) to find out how the surrounding context affects and c) to describe the linguistic features signaling all four contextual levels