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   groff_mm    ( 7 )

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Internals

The letter macros use different submacros depending on the letter type. The name of the submacro has the letter type as suffix. It is therefore possible to define other letter types, either in the territory-specific macro file, or as local additions. .LT sets the registers Pt and Pi to 0 and 5, respectively. The following strings and macros must be defined for a new letter type.

let@init_type This macro is called directly by .LT. It is supposed to initialize registers and other stuff.

let@head_type This macro prints the letter head, and is called instead of the normal page header. It is supposed to remove the alias let@header, otherwise it is called for all pages.

let@sg_type name title n flag [arg1 [arg2 [...]]] .SG is calling this macro only for letters; memorandums have its own processing. name and title are specified through .WA/.WB. n is the counter, 1-max, and flag is true for the last name. Any other argument to .SG is appended.

let@fc_type closing This macro is called by .FC, and has the formal closing as the argument.

.LO is implemented as a general option-macro. It demands that a string named Lettype is defined, where type is the letter type. .LO then assigns the argument to the string let*lo-type.