CATS_CHECK_PROFILE_AUTHORITY

HI Can anybody please tell me role of ACTION import parameter in Function module CATS_CHECK_PROFILE_AUTHORITY

   CALL FUNCTION 'CATS_CHECK_PROFILE_AUTHORITY'
      EXPORTING
        pernr                   = gv_empl
       begda                   = sy-datum
       endda                   = sy-datum
        variant                 = lv_variant
       ACTION                  = 'R'
     EXCEPTIONS
       pernr_not_found         = 1
       variant_not_found       = 2
       invalid_action          = 3
       no_authority            = 4
       OTHERS                  = 5.
    IF sy-subrc <> 0.
      IF sy-subrc = 2.
        MESSAGE text-016 TYPE C_i .
      ELSEIF sy-subrc = 4.
*        c_e r lv_variant gv_empl .
        MESSAGE text-072 TYPE C_i.
      ELSE.
        MESSAGE ID sy-msgid TYPE sy-msgty NUMBER sy-msgno
                WITH sy-msgv1 sy-msgv2 sy-msgv3 sy-msgv4.
      ENDIF.

Action can take two values. Lesen R, Erfassen E