Analogue marking are meaningful gestures that NLP practitioner make in their communication. As such it is part of the Miltonmodel.
Gesture and language. – Older than language is the mimicking of gestures, which takes place involuntarily and is even now, when the language of gesture is universally restrained and control of the muscles has been achieved, so strong that we cannot see a mobile face without an innervation of our own face (one can observe that feigned yawning will evoke real yawning in one who sees it). The imitated gesture leads him who imitates it back to the sensation which it expressed in the face or body of the person imitated. That is how people learned to understand one another: that is how a child still learns to understand its mother. In general, painful sensations may well also be expressed by gestures which in turn occasion pain (for example by pulling hair out, beating the breast, violent distortions and strainings of the facial muscles). Conversely, gestures of pleasure were themselves pleasurable and could thus easily convey their meaning (laughter as an expression of being tickled, which is pleasurable, again served as an expression of other pleasurable sensations). – As soon as the meaning of gestures was understood, a symbolism of gestures could arise: I mean a sign-language of sounds could be so agreed that at first one produced sound and gesture (to which it was symbolically joined), later only the sound. – It appears here that in earlier ages there often occurred that which now takes place before our eyes and ears in the evolution of music, especially of dramatic music: while music was at first empty noise without explanatory dance and mime (gesture-language), the ear was, through long habituation to the juxtaposition of music and movement, schooled to an instantaneous interpretation of the total figurations and has at last attained to a height of rapid understanding at which it no longer has any need of the visible movement and understands the tone-poet without it. One then speaks of absolute music, that is to say of music in which everything is at once understood symbolically without further assistance.
Human, All Too Human book 1, paragraph 216