Register and constitutive factors

Jakobson introduced the term `constitutive factors' for the features of context which characterise the functions of language in use. This kind of concept goes back to Bühler, who identified four constitutive factors:

1. The context: the `representational' function of language pertains to the relation between the sign and the world.
2. The speaker: the `expressive' function of language pertains to the relation between the speaker and the sign.
3. The addressee: the `appeal' function of language pertains to the relation between the addressee and the sign (Bühler compares this with `sex appeal').
4. The sign.

Jakobson's distinction goes further, but defines functions in much the same way:

1. The context: the relation between a message and the context is `representational'.
2. The speaker: the relation between a message and the speaker is `expressive'.
3. The addressee: the relation between a message and the addressee is `conative'.
4. The contact (channel): the relation between a message and the channel is `phatic'.
5. The code: the relation between a message and a code in which messages are formulated is `metalingual'.
6. The message (sign): the relation between a message and itself is `poetic'.

Hymes continued this tradition with a set of constitutive factors which he referred to with the acronym `SPEAKING'.

Task:

Find

• the meaning of the acronym `SPEAKING'.