the 2 isometry classes of irreducible [21,5,10]_2 codes are:

code no       1:
================
1 1 1 1 1 1 1 1 1 0 0 0 0 0 0 0 1 0 0 0 0
1 1 1 1 1 0 0 0 0 1 1 1 1 0 0 0 0 1 0 0 0
1 1 1 0 0 1 1 0 0 1 1 0 0 1 1 0 0 0 1 0 0
1 1 0 1 0 1 0 1 0 1 0 1 0 1 0 1 0 0 0 1 0
1 0 1 0 1 0 1 0 1 0 1 0 1 0 1 1 0 0 0 0 1
the automorphism group has order 1920
and is strongly generated by the following 5 elements:
(
1 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 
0 1 0 0 0 0 0 0 0 0 0 0 0 0 0 0 
0 0 1 0 0 0 0 0 0 0 0 0 0 0 0 0 
0 0 0 1 0 0 0 0 0 0 0 0 0 0 0 0 
0 0 0 0 1 0 0 0 0 0 0 0 0 0 0 0 
0 0 0 0 0 0 0 0 0 1 0 0 0 0 0 0 
0 0 0 0 0 0 0 0 0 0 1 0 0 0 0 0 
0 0 0 0 0 0 0 0 0 0 0 1 0 0 0 0 
0 0 0 0 0 0 0 0 0 0 0 0 1 0 0 0 
0 0 0 0 0 1 0 0 0 0 0 0 0 0 0 0 
0 0 0 0 0 0 1 0 0 0 0 0 0 0 0 0 
0 0 0 0 0 0 0 1 0 0 0 0 0 0 0 0 
0 0 0 0 0 0 0 0 1 0 0 0 0 0 0 0 
0 0 0 0 0 0 0 0 0 0 0 0 0 1 0 0 
0 0 0 0 0 0 0 0 0 0 0 0 0 0 1 0 
0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 1 
, 
1 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 
0 1 0 0 0 0 0 0 0 0 0 0 0 0 0 0 
0 0 1 0 0 0 0 0 0 0 0 0 0 0 0 0 
0 0 0 0 0 1 0 0 0 0 0 0 0 0 0 0 
0 0 0 0 0 0 1 0 0 0 0 0 0 0 0 0 
0 0 0 0 0 0 0 0 0 1 0 0 0 0 0 0 
0 0 0 0 0 0 0 0 0 0 1 0 0 0 0 0 
0 0 0 0 0 0 0 0 0 0 0 0 0 1 0 0 
0 0 0 0 0 0 0 0 0 0 0 0 0 0 1 0 
0 0 0 1 0 0 0 0 0 0 0 0 0 0 0 0 
0 0 0 0 1 0 0 0 0 0 0 0 0 0 0 0 
0 0 0 0 0 0 0 1 0 0 0 0 0 0 0 0 
0 0 0 0 0 0 0 0 1 0 0 0 0 0 0 0 
0 0 0 0 0 0 0 0 0 0 0 1 0 0 0 0 
0 0 0 0 0 0 0 0 0 0 0 0 1 0 0 0 
0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 1 
, 
1 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 
0 1 0 0 0 0 0 0 0 0 0 0 0 0 0 0 
0 0 0 1 0 0 0 0 0 0 0 0 0 0 0 0 
0 0 1 0 0 0 0 0 0 0 0 0 0 0 0 0 
0 0 0 0 1 0 0 0 0 0 0 0 0 0 0 0 
0 0 0 0 0 0 0 0 0 1 0 0 0 0 0 0 
0 0 0 0 0 0 0 0 0 0 0 1 0 0 0 0 
0 0 0 0 0 0 0 0 0 0 1 0 0 0 0 0 
0 0 0 0 0 0 0 0 0 0 0 0 1 0 0 0 
0 0 0 0 0 1 0 0 0 0 0 0 0 0 0 0 
0 0 0 0 0 0 0 1 0 0 0 0 0 0 0 0 
0 0 0 0 0 0 1 0 0 0 0 0 0 0 0 0 
0 0 0 0 0 0 0 0 1 0 0 0 0 0 0 0 
0 0 0 0 0 0 0 0 0 0 0 0 0 1 0 0 
1 1 0 1 0 1 0 1 0 1 0 1 0 1 0 1 
1 1 1 0 0 1 1 0 0 1 1 0 0 1 1 0 
, 
1 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 
1 1 0 1 0 1 0 1 0 1 0 1 0 1 0 1 
0 0 0 0 0 0 0 0 0 0 0 0 0 1 0 0 
0 0 0 0 0 0 0 0 0 0 0 1 0 0 0 0 
0 0 0 0 0 0 0 0 0 1 0 0 0 0 0 0 
1 0 1 0 1 0 1 0 1 0 1 0 1 0 1 1 
0 0 0 0 0 0 0 0 0 0 0 0 0 0 1 0 
0 0 0 0 0 0 0 0 0 0 0 0 1 0 0 0 
0 0 0 0 0 0 0 0 0 0 1 0 0 0 0 0 
0 0 0 0 0 0 0 1 0 0 0 0 0 0 0 0 
0 0 0 0 0 1 0 0 0 0 0 0 0 0 0 0 
0 0 0 1 0 0 0 0 0 0 0 0 0 0 0 0 
0 1 0 0 0 0 0 0 0 0 0 0 0 0 0 0 
0 0 0 0 0 0 0 0 1 0 0 0 0 0 0 0 
0 0 0 0 0 0 1 0 0 0 0 0 0 0 0 0 
1 1 1 0 0 1 1 0 0 1 1 0 0 1 1 0 
, 
1 1 1 1 1 1 1 1 1 0 0 0 0 0 0 0 
0 0 0 0 0 0 0 0 1 0 0 0 0 0 0 0 
0 0 0 0 0 0 0 1 0 0 0 0 0 0 0 0 
0 0 0 0 0 0 1 0 0 0 0 0 0 0 0 0 
0 0 0 0 0 1 0 0 0 0 0 0 0 0 0 0 
0 0 0 0 0 0 0 0 0 1 0 0 0 0 0 0 
0 0 0 0 0 0 0 0 0 0 1 0 0 0 0 0 
0 0 0 0 0 0 0 0 0 0 0 1 0 0 0 0 
0 0 0 0 0 0 0 0 0 0 0 0 1 0 0 0 
0 0 0 0 1 0 0 0 0 0 0 0 0 0 0 0 
0 0 0 1 0 0 0 0 0 0 0 0 0 0 0 0 
0 0 1 0 0 0 0 0 0 0 0 0 0 0 0 0 
0 1 0 0 0 0 0 0 0 0 0 0 0 0 0 0 
0 0 0 0 0 0 0 0 0 0 0 0 0 1 0 0 
0 0 0 0 0 0 0 0 0 0 0 0 0 0 1 0 
0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 1 
)
acting on the columns of the generator matrix as follows (in order):
(6, 10)(7, 11)(8, 12)(9, 13)(17, 18), 
(4, 10, 6)(5, 11, 7)(8, 12, 14)(9, 13, 15)(17, 18, 19), 
(3, 4)(6, 10)(7, 12)(8, 11)(9, 13)(15, 20)(16, 19)(17, 18), 
(2, 13, 8, 10, 5, 20)(3, 21, 6, 11, 9, 14)(4, 12)(7, 15)(16, 18, 19), 
(1, 18, 17)(2, 13, 9)(3, 12, 8)(4, 11, 7)(5, 10, 6)
orbits: { 1, 17, 18, 19, 16 }, { 2, 20, 9, 15, 5, 13, 11, 7, 10, 6, 8, 4, 12, 21, 14, 3 }

code no       2:
================
1 1 1 1 1 1 1 1 1 0 0 0 0 0 0 0 1 0 0 0 0
1 1 1 1 1 0 0 0 0 1 1 1 1 0 0 0 0 1 0 0 0
1 1 1 0 0 1 1 0 0 1 1 0 0 1 1 0 0 0 1 0 0
1 0 0 1 1 1 0 1 0 1 0 1 0 1 0 1 0 0 0 1 0
0 1 0 1 0 1 1 0 1 0 1 0 1 0 1 1 0 0 0 0 1
the automorphism group has order 1008
and is strongly generated by the following 9 elements:
(
1 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 
0 1 0 0 0 0 0 0 0 0 0 0 0 0 0 0 
0 0 0 0 0 1 0 0 0 0 0 0 0 0 0 0 
1 1 1 1 1 1 1 1 1 0 0 0 0 0 0 0 
0 0 0 0 1 0 0 0 0 0 0 0 0 0 0 0 
0 0 1 0 0 0 0 0 0 0 0 0 0 0 0 0 
0 0 0 0 0 0 1 0 0 0 0 0 0 0 0 0 
0 0 0 0 0 0 0 1 0 0 0 0 0 0 0 0 
0 0 0 0 0 0 0 0 1 0 0 0 0 0 0 0 
0 0 0 0 0 0 0 0 0 0 0 0 0 0 1 0 
0 0 0 0 0 0 0 0 0 0 0 0 0 1 0 0 
0 1 0 1 0 1 1 0 1 0 1 0 1 0 1 1 
1 0 0 1 1 1 0 1 0 1 0 1 0 1 0 1 
0 0 0 0 0 0 0 0 0 0 1 0 0 0 0 0 
0 0 0 0 0 0 0 0 0 1 0 0 0 0 0 0 
0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 1 
, 
1 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 
0 1 0 0 0 0 0 0 0 0 0 0 0 0 0 0 
0 0 0 1 0 0 0 0 0 0 0 0 0 0 0 0 
0 0 1 0 0 0 0 0 0 0 0 0 0 0 0 0 
0 0 0 0 1 0 0 0 0 0 0 0 0 0 0 0 
1 1 1 1 1 1 1 1 1 0 0 0 0 0 0 0 
0 0 0 0 0 0 1 0 0 0 0 0 0 0 0 0 
0 0 0 0 0 0 0 1 0 0 0 0 0 0 0 0 
0 0 0 0 0 0 0 0 1 0 0 0 0 0 0 0 
0 0 0 0 0 0 0 0 0 0 0 0 1 0 0 0 
0 0 0 0 0 0 0 0 0 0 0 1 0 0 0 0 
0 0 0 0 0 0 0 0 0 0 1 0 0 0 0 0 
0 0 0 0 0 0 0 0 0 1 0 0 0 0 0 0 
0 1 0 1 0 1 1 0 1 0 1 0 1 0 1 1 
1 0 0 1 1 1 0 1 0 1 0 1 0 1 0 1 
0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 1 
, 
1 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 
1 0 0 1 1 1 0 1 0 1 0 1 0 1 0 1 
0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 1 
1 1 1 0 0 1 1 0 0 1 1 0 0 1 1 0 
0 0 0 0 0 0 0 0 0 0 0 0 0 0 1 0 
0 0 0 0 0 1 0 0 0 0 0 0 0 0 0 0 
0 0 0 0 0 0 0 0 0 0 0 1 0 0 0 0 
0 0 0 0 0 0 0 0 0 0 1 0 0 0 0 0 
0 0 0 0 0 0 0 0 1 0 0 0 0 0 0 0 
0 0 0 0 0 0 0 0 0 1 0 0 0 0 0 0 
0 0 0 0 0 0 0 1 0 0 0 0 0 0 0 0 
0 0 0 0 0 0 1 0 0 0 0 0 0 0 0 0 
0 0 0 0 0 0 0 0 0 0 0 0 1 0 0 0 
0 0 0 0 0 0 0 0 0 0 0 0 0 1 0 0 
0 0 0 0 1 0 0 0 0 0 0 0 0 0 0 0 
0 0 1 0 0 0 0 0 0 0 0 0 0 0 0 0 
, 
1 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 
1 1 1 0 0 1 1 0 0 1 1 0 0 1 1 0 
0 0 0 0 0 0 0 0 0 0 0 0 0 0 1 0 
1 0 0 1 1 1 0 1 0 1 0 1 0 1 0 1 
0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 1 
0 0 0 0 0 0 0 0 0 1 0 0 0 0 0 0 
0 0 0 0 0 0 1 0 0 0 0 0 0 0 0 0 
0 0 0 0 0 0 0 1 0 0 0 0 0 0 0 0 
1 1 1 1 1 0 0 0 0 1 1 1 1 0 0 0 
0 0 0 0 0 1 0 0 0 0 0 0 0 0 0 0 
0 0 0 0 0 0 0 0 0 0 1 0 0 0 0 0 
0 0 0 0 0 0 0 0 0 0 0 1 0 0 0 0 
1 1 1 1 1 1 1 1 1 0 0 0 0 0 0 0 
0 0 0 0 0 0 0 0 0 0 0 0 0 1 0 0 
0 0 1 0 0 0 0 0 0 0 0 0 0 0 0 0 
0 0 0 0 1 0 0 0 0 0 0 0 0 0 0 0 
, 
1 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 
0 0 0 0 0 0 0 0 0 0 0 0 0 0 1 0 
1 1 1 0 0 1 1 0 0 1 1 0 0 1 1 0 
0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 1 
1 0 0 1 1 1 0 1 0 1 0 1 0 1 0 1 
0 0 0 0 0 1 0 0 0 0 0 0 0 0 0 0 
0 0 0 0 0 0 0 0 0 0 1 0 0 0 0 0 
0 0 0 0 0 0 0 0 0 0 0 1 0 0 0 0 
0 0 0 0 0 0 0 0 1 0 0 0 0 0 0 0 
0 0 0 0 0 0 0 0 0 1 0 0 0 0 0 0 
0 0 0 0 0 0 1 0 0 0 0 0 0 0 0 0 
0 0 0 0 0 0 0 1 0 0 0 0 0 0 0 0 
0 0 0 0 0 0 0 0 0 0 0 0 1 0 0 0 
0 0 0 0 0 0 0 0 0 0 0 0 0 1 0 0 
0 1 0 0 0 0 0 0 0 0 0 0 0 0 0 0 
0 0 0 1 0 0 0 0 0 0 0 0 0 0 0 0 
, 
1 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 
0 0 0 0 0 0 0 0 0 0 0 0 1 0 0 0 
1 1 1 0 0 1 1 0 0 1 1 0 0 1 1 0 
0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 1 
0 0 0 0 0 0 0 0 0 1 0 0 0 0 0 0 
0 0 0 1 0 0 0 0 0 0 0 0 0 0 0 0 
0 1 0 1 0 1 1 0 1 0 1 0 1 0 1 1 
0 0 0 0 0 0 0 0 0 0 0 0 0 1 0 0 
0 0 0 0 0 0 0 0 1 0 0 0 0 0 0 0 
1 0 0 1 1 1 0 1 0 1 0 1 0 1 0 1 
0 0 0 0 0 0 1 0 0 0 0 0 0 0 0 0 
0 0 0 0 0 0 0 1 0 0 0 0 0 0 0 0 
0 0 0 0 0 0 0 0 0 0 0 0 0 0 1 0 
0 0 0 0 0 0 0 0 0 0 0 1 0 0 0 0 
0 1 0 0 0 0 0 0 0 0 0 0 0 0 0 0 
0 0 0 0 0 1 0 0 0 0 0 0 0 0 0 0 
, 
0 0 0 0 0 0 0 1 0 0 0 0 0 0 0 0 
0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 1 
1 0 0 1 1 1 0 1 0 1 0 1 0 1 0 1 
0 0 0 0 0 0 0 0 0 0 0 0 1 0 0 0 
1 1 1 1 1 0 0 0 0 1 1 1 1 0 0 0 
0 0 0 0 0 0 0 0 0 1 0 0 0 0 0 0 
1 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 
0 0 0 0 0 0 1 0 0 0 0 0 0 0 0 0 
1 1 1 0 0 1 1 0 0 1 1 0 0 1 1 0 
0 0 0 0 0 1 0 0 0 0 0 0 0 0 0 0 
0 0 0 0 0 0 0 0 0 0 0 0 0 1 0 0 
0 0 0 0 0 0 0 0 0 0 1 0 0 0 0 0 
0 0 1 0 0 0 0 0 0 0 0 0 0 0 0 0 
0 0 0 0 0 0 0 0 0 0 0 1 0 0 0 0 
0 0 0 1 0 0 0 0 0 0 0 0 0 0 0 0 
0 0 0 0 0 0 0 0 1 0 0 0 0 0 0 0 
, 
0 1 0 1 0 1 1 0 1 0 1 0 1 0 1 1 
1 1 1 1 1 1 1 1 1 0 0 0 0 0 0 0 
1 0 0 1 1 1 0 1 0 1 0 1 0 1 0 1 
0 0 0 0 1 0 0 0 0 0 0 0 0 0 0 0 
1 1 1 1 1 0 0 0 0 1 1 1 1 0 0 0 
0 1 0 0 0 0 0 0 0 0 0 0 0 0 0 0 
1 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 
0 0 0 0 0 0 0 0 0 0 0 0 0 1 0 0 
0 0 0 0 0 1 0 0 0 0 0 0 0 0 0 0 
1 1 1 0 0 1 1 0 0 1 1 0 0 1 1 0 
0 0 0 0 0 0 1 0 0 0 0 0 0 0 0 0 
0 0 0 0 0 0 0 0 0 0 1 0 0 0 0 0 
0 0 1 0 0 0 0 0 0 0 0 0 0 0 0 0 
0 0 0 0 0 0 0 0 0 0 0 1 0 0 0 0 
0 0 0 1 0 0 0 0 0 0 0 0 0 0 0 0 
0 0 0 0 0 0 0 0 1 0 0 0 0 0 0 0 
, 
0 0 0 1 0 0 0 0 0 0 0 0 0 0 0 0 
0 0 0 0 0 0 0 0 0 1 0 0 0 0 0 0 
0 0 0 0 0 0 0 0 0 0 0 1 0 0 0 0 
1 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 
0 0 0 0 1 0 0 0 0 0 0 0 0 0 0 0 
0 0 0 0 0 0 0 1 0 0 0 0 0 0 0 0 
0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 1 
0 0 0 0 0 1 0 0 0 0 0 0 0 0 0 0 
1 0 0 1 1 1 0 1 0 1 0 1 0 1 0 1 
0 1 0 0 0 0 0 0 0 0 0 0 0 0 0 0 
1 1 1 1 1 0 0 0 0 1 1 1 1 0 0 0 
0 0 1 0 0 0 0 0 0 0 0 0 0 0 0 0 
0 0 0 0 0 0 0 0 0 0 0 0 1 0 0 0 
1 1 1 1 1 1 1 1 1 0 0 0 0 0 0 0 
0 0 0 0 0 0 0 0 0 0 0 0 0 0 1 0 
0 0 0 0 0 0 1 0 0 0 0 0 0 0 0 0 
)
acting on the columns of the generator matrix as follows (in order):
(3, 6)(4, 17)(10, 15)(11, 14)(12, 21)(13, 20), 
(3, 4)(6, 17)(10, 13)(11, 12)(14, 21)(15, 20), 
(2, 20)(3, 16)(4, 19)(5, 15)(7, 12)(8, 11), 
(2, 19)(3, 15)(4, 20)(5, 16)(6, 10)(9, 18)(13, 17), 
(2, 15)(3, 19)(4, 16)(5, 20)(7, 11)(8, 12), 
(2, 15, 13)(3, 17, 19)(4, 6, 16)(5, 20, 10)(7, 11, 21)(8, 12, 14), 
(1, 7, 8)(2, 18, 5, 19, 9, 16)(3, 13, 4, 15, 17, 20)(6, 10)(11, 12, 14), 
(1, 7, 11, 12, 14, 8, 21)(2, 6, 9, 16, 20, 3, 13, 19, 10, 18, 5, 4, 15, 17), 
(1, 4)(2, 10)(3, 12)(6, 8)(7, 16)(9, 20)(11, 18)(14, 17)(19, 21)
orbits: { 1, 8, 21, 4, 11, 12, 14, 7, 6, 19, 17, 3, 20, 16, 13, 5, 18, 10, 2, 15, 9 }