1-9. FORMS AND RECORDS.
Army aviators light record and aircraft maintenance records which are to be used by crewmembers are prescribed
in DA PAM 738-751 and Weight and Balance manual TM 55-1500-342-23.
1-10. EXPLANATION OF CHANGE SYMBOLS.
Except as noted in this paragraph, changes to the text and tables, including new material on added pages, are
indicated by a vertical line in the outer margin extending close to the entire area of the material affected. Exception:
pages with emergency markings, which consist of black diagonal lines around three edges, shall have the vertical
line or change symbol placed along the outer margins between the text and the diagonal lines. Symbols show current
changes only. A miniature pointing hand symbol is used to denote a change to an illustration. However, a vertical
line in the outer margin, rather than miniature pointing hands, is utilized when there have been extensive changes
made to an illustration. Change symbols are not utilized to indicate changes in the following:
Indexes and tabular data where the change cannot be identiied.
Blank space resulting from the deletion of text, an illustration, or a table.
Correction of minor inaccuracies, such as spelling, punctuation, relocation of material, etc., unless correc-
tion changes the meaning of instructive information and procedures.
1-11. AIRCRAFT DESIGNATION SYSTEM.
The designation system prescribed by AR 70-50 is used in aircraft designations as follows: EXAMPLE RC-12X
C-Basic mission and type symbol (Cargo)
1-12. USE OF WORDS SHALL, WILL, SHOULD, AND MAY.
Within this technical manual the word "shall" is used to indicate a mandatory requirement. The word "will" is used to
express a declaration of purpose or procedural result. The word "should" is used to indicate a non-mandatory but
preferred method of accomplishment. The word "may" is used to indicate an acceptable method of accomplishment.
1-13. PLACARD ITEMS.
Where applicable, placarded items (switches, controls, etc.) are shown, throughout this manual, in boldface capital