What is the meaning and syntax of the 'DEF LINE TEMPLATE' directive in FME Plugin Reader Writer metafiles

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Q) What is the meaning and syntax of the 'DEF LINE TEMPLATE' directive in FME Plugin Reader Writer metafiles?

A) This directive will determine the syntax for the DEF lines that workbench writes out. It is important that any parameters you define in the WORKBENCH_DEFLINE_PARMS section appear here, or else they won't actually show up in the DEF lines. If {FME_GEN_GEOMETRY} is provided on a def line, then DEF_LINE_BREAK must have the value GEOM_CHANGE.