a.
Introductory material.
b.
Indexes and tabular data where the change
cannot be identified.
c.
Blank space resulting from the deletion of text,
an illustration or a table.
d.
Correction of minor inaccuracies, such as
spelling, punctuation, relocation of material, etc.
, unless correction 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-
12D
R - Modified mission symbol (reconnaissance)
TM 55-1510-219-10
C - Basic mission and type symbol (cargo)
12 - Design number
D - Series symbol
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
"should" is used to indicate a nonmandatory but
preferred method of accomplishment. The word "may"
is
used
to
indicate
an
acceptable
method
of
accomplishment. The word "will" is used to express a
declaration of purpose and may also be used where
simple futurity is required.
1-13. PLACARD ITEMS.
All placard items (switches, controls, etc. ) are
shown throughout this manual in capital letters.
1-2
