Martin (1992: 32-3):
Semantically oriented labels of this kind highlight the meaning of the grammatical terms … and are used throughout Halliday (1985) [An Introduction To Functional Grammar] to focus on the grammar as a functionally organised meaning making resource (rather than as a syntax or set of forms). No attempt is made to distinguish stratally between grammar and meaning; rather the grammar in [is] infused with meaning, and a stratal distinction between grammar and semantics [is] systematically blurred. In this book however, an attempt will be made to unpick the boundary between grammar and semantics…
 The stratal distinction between grammar and semantics is not "systematically blurred". In the theoretical architecture of SFL, the content plane is stratified into semantics and lexicogrammar. The stratal distinction that this makes is between meaning and wording. The principal reason for doing so was the advantage it gave in being able to account for grammatical metaphor. Halliday & Matthiessen (1999: 237):
Of course, what we are recognising here as two distinct constructions, the semantic and the grammatical, never had or could have had any existence the one prior to the other; they are our analytic representation of the overall semioticising of experience — how experience is construed into meaning. If the congruent form had been the only form of construal, we would probably not have needed to think of semantics and grammar as two separate strata: they would be merely two facets of the content plane, interpreted on the one hand as function and on the other as form.
 The grammar is not infused with meaning — the grammar realises meaning. The grammar (wording) is at a lower level of symbolic abstraction than the semantics (meaning).
A functional grammar is a grammar viewed 'from above', because explaining functionality gives priority to the view 'from above'. This means giving priority to the view from higher levels of symbolic abstraction, which means viewing the grammar from semantics, in terms of stratification, and from system, in terms of axis. Halliday & Matthiessen (2004: 31):
Being a 'functional grammar' means that priority is given to the view 'from above'; that is, grammar is seen as a resource for making meaning — it is a 'semanticky' kind of grammar. But the focus of attention is still on the grammar itself.
Giving priority to the view ‘from above’ means that the organising principle adopted is one of system: the grammar is seen as a network of interrelated meaningful choices. In other words, the dominant axis is the paradigmatic one: the fundamental components of the grammar are sets of mutually defining contrastive features. Explaining something consists not of stating how it is structured but in showing how it is related to other things: its pattern of systemic relationships, or agnateness (agnation).