The terms of 1 by 2, 2 by 1, 2 by 2, 1 by 3, and 2 by 3 are talking about the positioning of letters in the call sign with respect to the regional number. 

The regional number separates the 2 sets of letters.

 Geographical Area for the region numbers.

1 -- CT, ME, MA, NH, RI, and VT

2 -- NJ and NY

3 -- DE, DC, MD, and PA

4 -- AL, FL, GA, KY, NC, SC, TN, and VA

5 -- AR, LA, MS, NM, OK, and TX

6 -- CA

7 -- AZ, ID, MT, NV, OR, UT, WA, and WY

8 -- MI, OH, and WV

9 -- IL, IN and WI

0 -- CO, IA, KS, MN, NE, MO, ND, and SD

GROUP	LICENSE CLASS	CALL SIGN FORMAT
Group A	Extra	1-by-2 call signs beginning with the prefix letter K, N or W; 2-by-1 call signs beginning with the prefix letters AA to AK, KA to KZ, NA to NZ and WA to WZ; 2-by-2 call signs beginning with the prefix letters AA to AK. Certain two letter prefixes are not available to mainland U.S. radioamateurs.
Group B	Advanced	2-by-2 call signs beginning with the prefix letters KA to KZ, NA to NZ and WA to WZ - not AA-AK
Group C	Technician Tech Plus General	1-by-3 call sign formats beginning with K, N or W -- but not the prefix letter "A"
Group D	Novice	2-by-3 call sign formats beginning with KA to KZ and WA to WZ - but not NA-NZ