Martin (1992: 389-90):
The relationship of SPEECH FUNCTION to MOOD mediated by interpersonal metaphor is precisely parallel to that between CONJUNCTION and the clause complex as mediated by ideational metaphor. Because of this it was possible to present a register neutral description of the semantics of dialogue in Chapter 2, just as it was possible to produce a register neutral description of conjunctive relations in Chapter 4. Both these types of organic relation are essential components of English text forming resources and need to be interpreted systematically as semantic systems in language, not as register specific features of context.
 This is untrue. Speech function and mood are both interpersonal systems — at the level of semantics and lexicogrammar respectively — and the relationship between them is realisation (congruent or metaphorical). However, whereas clause complexing is a manifestation of the logical metafunction in lexicogrammar, Martin's discourse semantic system of conjunction takes as its point of departure the textual system of cohesive conjunction. Because this cohesive system is the textual deployment of expansion relations, the other major logico-semantic type, projection, is absent from the discourse semantic model. This is a major theoretical shortcoming, since clause complexes involving projection are not accounted for semantically. Crucially, this in turn removes the means of distinguishing congruent vs metaphorical realisations in the grammar.
 The realisation relation between strata is not "mediated" by grammatical metaphor. Realisations are either congruent or metaphorical, the latter being a manifestation of the textual metafunction as a second-order resource (Halliday & Matthiessen 1999: 398-9).
 The realisation relation between strata applies to all systems on all strata. It does not provide a special means of presenting "register neutral" descriptions for two of the four discourse semantic systems.
 In SFL theory, the relation between the general system of semantic potential and the semantic systems of specific registers is theorised as instantiation. The interpersonal semantic systems of specific registers are termed exchange relationships. Halliday & Matthiessen (1999: 377-8):
Midway between potential and instance, sets of such strategies cluster within ranges of tenor values. Such a cluster is the interpersonal analogue of a domain in the ideation base: it is a region within the overall interpersonal space of meaning, selected according to tenor, just as a domain is a region within the overall ideational space of meaning, selected according to field. The options in interpersonal meaning that make up the cluster together enact a tenor relationship … We might call such a cluster an exchange relationship to foreground that it is semantic (i.e. constituted in meaning through exchanges of meaning) and that it is interpersonal (rather than one-sidedly personal). To indicate that it is analogous to a domain model, we might have called it an exchange or interaction “model”; but we have avoided that term because it suggests a construal of something and construal is the ideational mode of meaning — it is more like a protocol than a model.
 To be clear, the term 'organic relation' is used by Hasan (1985: 81) with respect to the textual metafunction: to differentiate conjunction from the other ('componential') types of cohesion:
These devices are ORGANIC; the terms in the tie are whole message(s) rather than message components…
 In SFL theory, the text forming resources are the systems of the textual metafunction. In discourse semantics, the systems of all metafunctions are said to be text forming.
 To be clear, in SFL theory, 'register specific features of context' are the features of specific situation types (field, tenor and mode) that are realised by specific registers of language. This is not what Martin means. See the critiques of field in Chapter 5.