Abap statement

Question

what does this mean
NOT t_salesdoc-matkl IN s_matkl
and also what could be the meaning of this
IF p_pcnt01 IS INITIAL.
        IF t_salesdoc-faksk IS INITIAL.
          t_salesdoc-faksk = k_01.
        ENDIF.
        t_salesdoc-no_percent = k_x.
        READ TABLE i_vbpa WITH KEY vbeln = t_salesdoc-vbeln.
        IF sy-subrc = 0.
          IF lv_flag IS INITIAL.
            WRITE: 'Pricing adjustment for Credit memo amount (A/R)'.
            SKIP.
            lv_flag = 'X'.
          ENDIF.
          WRITE: / 'Order:'(004),t_salesdoc-vbeln, t_salesdoc-posnr,
                 'Customer:'(005),i_vbpa-kunnr,
                 'CM Method:'(100),t_salesdoc-katr5,
                 'Pricing method missing'(006).
        ENDIF.

Answer 1

Hi,
1.NOT t_salesdoc-matkl IN s_matkl
means
t_salesdoc-matkl should not be there in s_matkl
2.IF p_pcnt01 IS INITIAL.
IF t_salesdoc-faksk IS INITIAL
means
if p_pcnt01 has no value
and
if t_salesdoc-faksk has no value.
3.IF lv_flag IS INITIAL
means
lv_flag has no value or initial value ie to check whether the flag is set or not.
Reward if helpful.
Regards.