Figure 1-6. Control Abbreviations and Symbols (Concluded).
(2) Handprinted characters and plain language markings. When you believe a misunderstanding
might occur in the standard recording of handprinted characters, underline "Ss" (S) and cross zeros (0).
Use plain language markings to supplement the preceding when it aids in understanding the recorded
(3) Locally approved identifiers. Use locally approved identifiers for frequently used fixes in
lieu of those listed in the location identifier's handbook. Use these identifiers only within your facility
and not on teletypewriter or interphone circuits.
NOTE: Use plain sheets of paper to record information when flight progress strips are not feasible.