Effect if VGA CRTC Mode Control DIV2 bit on text modes

[superfury]

Anyone knows what effect the DIV2 bit of the CRTC mode control register has on text mode display? Does it double every horizontal character? Or does it double all pixels?

DIV2 -- Divide Memory Address clock by 2
"When this bit is set to 0, the address counter uses the character clock. When this bit is set to 1, the address counter uses the character clock input divided by 2. This bit is used to create either a byte or word refresh address for the display buffer."