In much of the research currently conducted upon various phenomena of non-referential indexicality, there is an increased interest in not only what is called first-order indexicality, but subsequent second-order as well as "higher-order" levels of indexical meaning. First-order indexicality can be defined as the first level of pragmatic meaning that is drawn from an utterance. For example, instances of deference indexicality such as the variation between informal "Tu" and the more formal "Vous" in French (See T/V deference indexes) indicate a speaker/addressee communicative relationship built upon the values of 'power' and 'solidarity' possessed by the interlocutors. When a speaker addresses somebody using the V form instead of the T form, they index (via first-order indexicality) their understanding of the need for deference to the addressee. In other words, they perceive/ recognize an incongruence between their level of 'power' and/or 'solidarity', and that of their interlocutor and employ a more formal way of addressing that person to suit the contextual constraints of the speech event.