The naming prefix part shieldo- was made up ad hoc, kind of corresponding to the similar prefix rhombi- for the digonal counterpart of the trigonal one in this case. It also corresponds to the fact that semiregular polygons with equal edges but alternating angles are commonly called rhombs, shields, etc. Nonetheless, the here used hexagons are regular ones, just as the tetragons in the related cases are true squares. It is only that both are positioned within a lower surrounding symmetry.

Incidence matrix according to Dynkin symbol

x3x3o∞*a   (N,M → ∞)

. . .    | 3NM |   2   2 |  2  1  1
---------+-----+---------+---------
x . .    |   2 | 3NM   * |  1  1  0
. x .    |   2 |   * 3NM |  1  0  1
---------+-----+---------+---------
x3x .    |   6 |   3   3 | NM  *  *
x . o∞*a |   M |   M   0 |  * 3N  *
. x3o    |   3 |   0   3 |  *  * NM