011 What should be the sequence of multiple attributive adjectives?

Order of adjectives placed before nouns

Adjectives describe nouns (and noun-phrases).
Attributive adjectives precede the nouns.
We can use any number of attributive adjectives before the nouns; hence the term 'multiple attributive adjectives'.

What should be the order or sequence of multiple attributives adjectives?

Formula: OSQ ShAC NMTP.

O = Opinion (adjectives which express opinions e.g. good, bad, etc.).
S = Size (big, small etc.).
Q = Quantity (physical quantity).
Sh = Shape.
A = Age.
C = Color.
N = Number.
M = Material.
T = Type.
P = Purpose.

E.g. Accordion is a portable musical instrument.

This sentence follows the sequence of 'TP'.
Portable - an adjective of type.
Musical - is the adjective of purpose.

Let us rewrite the sentence:

Accordion is a musical portable instrument.

This cannot be wrong, theoretically, but the order looks awkward, because it is not in use.

*I am unable to trace the authority for this principle/practice.
*I shall try to quote the authority here, as soon as I am able to trace.
*Using this principle improves clarity of the sentence.
*Dividing line between different types of adjectives, can sometimes be, thin.