Pressing a 0-9 digit accumulates that digit into what is named
the "modifier". That modifier affects the behavior of many
keystokes described below. The modifier starts at zero, but
most commands interpret a zero as a 1 so that they can have an
effect.

'G' selects the block specified by the modifier as the current
block. Any change madde to the previously selected block is
saved beforehand.

'[' and ']' advance the selected block by modifier.

';' resets the modifier

H and L move the cursor by "modifier" characters. J and K, by
lines.                                                  (cont.)