qmk_firmware/keyboards/68keys/68keys.h

#include "quantum.h"

#define LAYOUT_68_ansi(                                                             \
    K00, K01, K02, K03, K04, K05, K06, K07, K08, K10, K11, K12, K13, K14, K15, K16, \
    K17, K18, K20, K21, K22, K23, K24, K25, K26, K27, K28, K30, K31, K32, K33, K34, \
    K35, K36, K37, K38, K40, K41, K42, K43, K44, K45, K46, K47, K48,                \
    K50, K51, K52, K53, K54, K55, K56, K57, K58, K60, K61, K62, K63,                \
    K64, K65, K66, K67, K68, K70, K71, K72, K73, K74)                               \
    {                                                                               \
        {K00, K01, K02, K03, K04, K05, K06, K07, K08},                              \
            {K10, K11, K12, K13, K14, K15, K16, K17, K18},                          \
            {K20, K21, K22, K23, K24, K25, K26, K27, K28},                          \
            {K30, K31, K32, K33, K34, K35, K36, K37, K38},                          \
            {K40, K41, K42, K43, K44, K45, K46, K47, K48},                          \
            {K50, K51, K52, K53, K54, K55, K56, K57, K58},                          \
            {K60, K61, K62, K63, K64, K65, K66, K67, K68},                          \
        {                                                                           \
            K70, K71, K72, K73, K74                                                 \
        }                                                                           \
    }