What is a make sense (meaningful) example of language that an unrestricted grammar could generate?


I have learned that:

  1. Unrestricted grammar is used to define (or describe) a formal language.
  2. Unrestricted grammar is used to define recursively enumerable set [https://en.wikipedia.org/wiki/Recursively_enumerable_set][1].

I’d like to find a meaningful example for #1 case which is similar to below context sensitives grammar example to learn the purpose of unrestricted grammar. I could find a meaningful example for context sensitives grammar but I could not find a one for the unrestricted grammar yet. Could you help me?

Language for “Network racing game record” with below record instances:

Mr. Bean Male Player 1

Ms. Emma Female Player 2

Mr. Hải n/a Computer 3

Ms. Tú n/a Computer 4

Production rule:

S ⟶ Title Name TAB Sex UserType TAB Rank

Title WomanName ⟶ "Ms. " WomanName

Title ManName ⟶ "Mr. " ManName

WomanName TAB Sex "Player" ⟶ WomanName TAB "Female" "Player"

ManName TAB Sex "Player" ⟶ ManName TAB "Male" "Player"

Name TAB Sex "Computer" ⟶ Name TAB "n/a" "Computer"

Name ⟶ WomanName

Name ⟶ ManName

Sex ⟶ "Male"

Sex ⟶ "Female"

UserType ⟶ "Player"

UserType ⟶ "Computer"

Rank ⟶ "1"

Rank ⟶ "2"

Rank ⟶ "3"

Rank ⟶ "4"

WomanName ⟶ "Emma"

WomanName ⟶ "Tú"

ManName ⟶ "Bean"

ManName ⟶ "Hải"

TAB ⟶ "\t"