Resources are available as a reservoir for recruitment by strategies in the compilation of a repertoire. The resource level is the most subordinate level of the machine, so that the degree of arbitrariness (ie in respect of the selection of particular resources) is maximised. An example of a resource is signifying mode which:

... describes a form of the relationship between expression and content that is implicated in sign production. That is, Saussure’s contention that the general relationship between signifier and signified is one of arbitrariness is being rejected, here; rather, this relationship is understood as being motivated (see Hodge & Kress, 1988, 1993; Kress, 1993). There are diverse ways in which such motivation can be realised. ‘Signifying mode’ refers to a particular repertoire of resources which is implicated in localising and generalising strategies. Furthermore, these particular resources can be described with sufficient precision to enable a content analysis of the empirical texts.
(Dowling, 1998; p. 151)

For example, the iconic signifying mode employed in most school texts invokes a visual code of presence which strengthens the 'modality' (or the strength of the claim to a reality beyond the text; see Hodge & Kress, 1988) of the signification vis a vis the symbolic mode (the mode dominating written text). Further, this 'modality' is weakened as the specific form of icon moves between realist photograph, realist drawing, and cartoon (see Dowling, 1998).