Labels in edit macros

A label is an alphabetic character string used to name lines. It is especially useful for keeping track of a line whose relative line number may change because labels remain set on a line even when relative line numbers change. The special labels shown are automatically assigned by the editor. A label must begin with a period (.) and be followed by no more than 8 alphabetic characters, the first of which cannot be Z. No special characters or numeric characters are allowed.

The special labels that are automatically assigned by the editor all begin with the letter Z. Labels beginning with Z are reserved for editor use only.

The editor-assigned labels are:
.ZCSR
The data line on which the cursor is currently positioned.
.ZFIRST
The first data line (same as relative line number 1). Can be abbreviated .ZF.
.ZLAST
The last data line. Can be abbreviated .ZL.
.ZFRANGE
The first line in a range specified by you.
.ZLRANGE
The last line in a range specified by you.
.ZDEST
The destination line specified by you.
Note: Unlike other labels, .ZCSR, .ZFIRST, and .ZLAST do not stay with the same line. Label .ZCSR stays with the cursor, and labels .ZFIRST and .ZLAST point to the current first and last lines, respectively.