The .NUMBER LEVEL command allows you to specify the beginning
    number of a sequence of headers. Enter this command immediately
    before the first .HEADER LEVEL command that you want to affect.
    Subsequent .HEADER LEVEL commands will each be one higher than
    the preceding one according to its level (see .HEADER LEVEL).
    (See also .STYLE HEADERS and .DISPLAY LEVELS.)

    Format

      .NUMBER LEVEL  [[+/-]n1] [,[+/-]n2]...[,[+/-]n6]

    Abreviated format

      .NMLV  [[+/-]n1] [,[+/-]n2]...[,[+/-]n6]

1  –  Parameters

 n1,n2,...n6

    Indicate positioned numbers in a section header. The commas
    correspond to the dots in the printed section number. For
    example, to set the next .HEADER LEVEL to 3.5.2.4, you would
    enter the following commands:

       .NUMBER LEVEL 3,5,2,4
       .HEADER LEVEL

 +nN

    Adds n to the current value of the parameter N.

 -nN

    Subtracts n from the current value of the parameter N.

2  –  Default

    Sequential decimal numbering, beginning with 1.