You can refer to data lines either by a relative line number or by a symbolic label. Note that special lines (MASK lines, TABS lines, COLS lines, BOUNDS lines, MSG lines, and others) are not considered data lines. You cannot assign labels to them, and they do not have relative line numbers. Also, you cannot directly reference these lines in a macro, even though they are displayed. Excluded lines are regarded as data lines.

Relative line numbers are not affected by sequence numbers in the data, nor are they affected by the current setting of number mode. The first line of data is always treated as line number 1, the next line is line number 2, and so on. The TOP OF DATA line is considered line number 0.

When you insert or delete lines, the lines that follow change relative line numbers. If you insert a new line after line 3, for example, it becomes relative line 4 and what was relative line 4 becomes relative line 5, and so on. Similarly, if line 7 is deleted, the line that was relative line 8 becomes relative line 7, and so on.