Another useful item is the Jaguar Reference Manual

Datasheets

Expansion Cartridge Pins

ROM1 is the chip enable for the cart ROM.

WAITL and RESETL are the outputs from the Jaguar, they are WAIT from the 68k and the system RESET.

RESETIL is the input from the cartridge side for causing a reset (I use this).

E2DATA is the EEPROM used on some carts for save data.

GPIO are chip enables for specific parts of the memory map, some of these are also used on the GD.

SCK, WS, TXD and RXD are the I2S bus used for CD audio.

EWE, ERW, EOE are write enable, direction (read/write) and output enable for the data bus.

All of these are documented well in the reference manual above.