document ~| format modifier to place a tab stop at this position
This works best when used in tandem with ~N+, since it is currently
equivalent to ~0| and does not take the actual text position into account.
However, when using relative positions, this works as intended.
if N is 0 or omitted, no decimal point is used.
~ND like ~Nd, separating digits to the left of the decimal point
in groups of three, using the character "," (comma)
+ ~| place a tab stop at this position
~N| where N is an integer: place a tab stop at text column N
~N+ where N is an integer: place a tab stop N characters
after the previous tab stop (or start of line)
