Q:

Word or phrase that describes a group of acronymic initials that can be any order

Typical acronyms represent a phrase with a fixed word order. For example, NATO (North Atlantic Treaty Organization) is not coherent when reordered to, say, ATNO (Atlantic Treaty North Organization).
Yet a form of 'anagrammatic acronyms' exists where each word stands alone and can be represented in any order (although by convention, one order may be culturally dominant): 

Big five personality traits as OCEAN, NEOAC, CANOE, etc;
The elements of art as SFTSLVC, TFCSSVL, etc;
The fire triangle as OHF, HFO, etc.

What do linguists call a collection of word initials that may not mnemonic and can be in any order that pleases the reader or author?

A:

Commutative = where changing the order of words or item would not affect the outcome or meaning of the phrase or equation.
Commutative, as applied to a binary operation, by extension of logic and grouping would apply to triplets, quadruplets, ... and n-tuplets as well. For example, hierarchical commutation of pairs
((a . b) . c) = ((a . c) . b) = ((c . b) . a) = (a . b . c) = (c . a . b), etc.

com•mu•ta•tive  (kŏm′yə-tā′tĭv, kə-myo̅o̅′tə-tĭv)
  adj.  

Relating to, involving, or characterized by substitution, interchange, or exchange.
Independent of order. Used of a logical or mathematical operation that combines objects or sets of objects two at a time. If a × b = b × a, the operation indicated by × is commutative.  

com•mu′ta•tiv′i•ty (kə-myo̅o̅′tə-tĭv′ĭ-tē) n.
commutative (kəˈmjuːtətɪv; ˈkɒmjʊˌteɪtɪv)
  adj

relating to or involving substitution
(Mathematics) maths logic
  a. (of an operator) giving the same result irrespective of the order of the arguments; thus disjunction and addition are commutative but implication and subtraction are not
  b. relating to this property: the commutative law of addition.
(Logic) maths logic
  a. (of an operator) giving the same result irrespective of the order of the arguments; thus disjunction and addition are commutative but implication and subtraction are not
  b. relating to this property: the commutative law of addition.
  comˈmutatively adv
  

For example, commutative grammar of certain synthetic languages, where English have scantly such properties.

She loved him
She him loved
Loved him she
Loved she him
Him she loved
Him loved she

