Preamble: Every mapping function is identified by the subscripted name that follows its right-hand bold square bracket. For a few mapping functions, the subscript also contains a parameter, which is usually a metavariable, e.g. 'Type1' in [[ ... ]]_FunctionArgument(Type1) Currently, when a metavariable occurs as a mapping's subscript-parameter, it is rendered abnormally (relative to the rendering of metavariables everywhere else): -- It is shown in an upright font (vs slanted/italic). -- If it itself has a 'subscript', that subscript appears on the same baseline (vs being on a lowered baseline). Both effects can be seen in 4.1.5 [Function Calls] / Normalization / rule 1 Instead, metavariables appearing in mapping function subscripts should be rendered as they are elsewhere.
This issue has been entered as FS erratum E051, and the fix has been committed to the source files for the next edition of the FS document. Consequently, I'm marking this issue resolved-FIXED, and CLOSED.