Hi Dave,
I suspect they're talking about SHIFTIN/SHIFTOUT (for SPI) and I2CIN/I2COUT for I2C.

There's no support for hardware (MSSP module) driven synchronous communication (like it is for the (E)USART with HSERIN/HSEROUT), however it's not very hard to do "manually", at least not SPI. It seems a bit more complicated to set the MSSP module up for I2C but I've never actually done it so...

/Henrik.