This spaces over to a given column. `~`*colnum*`,`*colinc*`T` will output sufficient spaces to move the cursor to column *colnum*. If the cursor is already at or beyond column *colnum*, it will output spaces to move it to column *colnum*+*k***colinc* for the smallest positive integer *k* possible, unless *colinc* is zero, in which case no spaces are output if the cursor is already at or beyond column *colnum*. *colnum* and *colinc* default to `1`.

If for some reason the current absolute column position cannot be determined by direct inquiry, **format** may be able to deduce the current column position by noting that certain directives (such as `~%`, or `~&`, or `~A` with the argument being a string containing a newline) cause the column position to be reset to zero, and counting the number of characters emitted since that point. If that fails, **format** may attempt a similar deduction on the riskier assumption that the destination was at column zero when **format** was invoked. If even this heuristic fails or is implementationally inconvenient, at worst the `~T` operation will simply output two spaces.

`~@T` performs relative tabulation. `~`*colrel*`,`*colinc*`@T` outputs *colrel* spaces and then outputs the smallest non-negative number of additional spaces necessary to move the cursor to a column that is a multiple of *colinc*. For example, the directive `~3,8@T` outputs three spaces and then moves the cursor to a ``standard multiple-of-eight tab stop'' if not at one already. If the current output column cannot be determined, however, then *colinc* is ignored, and exactly *colrel* spaces are output.

If the *colon* modifier is used with the `~T` directive, the tabbing computation is done relative to the horizontal position where the section immediately containing the directive begins, rather than with respect to a horizontal position of zero. The numerical parameters are both interpreted as being in units of *ems* and both default to `1`. `~`*n*`,`*m*`:T` is the same as `(pprint-tab :section `*n*` `*m*`)`. `~`*n*`,`*m*`:@T` is the same as `(pprint-tab :section-relative `*n*` `*m*`)`.