Section 27-618. Identification

Except as provided for in subdivisions (a)
  and (c) of this section, all wood used for structural elements shall  be
  identified as to grade and shall bear an identifying mark of an approved
  bureau  or agency performing the grading, or the official grade mark and
  trade mark of the bureau or association under whose rules the  wood  was
  graded, in accordance with the following:
    (a)  Lumber  and  timber.  All lumber and timber, including non-stress
  grade lumber, shall be identified by the grade mark of a lumber  grading
  or inspection bureau or agency approved by the commissioner, except that
  pre-cut  material  and rough-sawn lumber may be covered by a certificate
  of inspection issued by a lumber grading or inspection  agency  approved
  by the commissioner in lieu of grade marking.
    (b) Plywood. Plywood used structurally shall bear identification as to
  grade,   type,   and   species  group,  or  identification  index.  Such
  identification shall be affixed by and identified by the trademarks of a
  testing and grading agency approved by the commissioner.
    (c) Glued-laminated. Glued-laminated  structural  members  shall  bear
  identification   and/or   shall   be  accompanied  by  certification  in
  accordance with the provisions of reference standard RS 10-18.
    (d) Resawn lumber. Resawn  (or  reused)  lumber  shall  be  marked  in
  accordance with its regraded status.