+
+@subsubheading Numeric Attributes
+
+These attributes are used for formats when @code{baseFormat} is
+@code{number}. Attributes @code{maximumFractionDigits}, and
+@code{minimumFractionDigits}, and @code{useGrouping} are also used
+when @code{baseFormat} is @code{elapsedTime}.
+
+@defvr {Attribute} minimumIntegerDigits
+Minimum number of digits to display before the decimal point. Always
+observed as @code{0}.
+@end defvr
+
+@defvr {Attribute} maximumFractionDigits
+@defvrx {Attribute} maximumFractionDigits
+Maximum or minimum, respectively, number of digits to display after
+the decimal point. The observed values of each attribute range from 0
+to 9.
+@end defvr
+
+@defvr {Attribute} useGrouping
+Whether to use the grouping character to group digits in large
+numbers. It would make sense for the grouping character to come from
+the @code{separatorChars} attribute, but that attribute is only
+present when @code{baseFormat} is @code{dateTime} or
+@code{elapsedTime}, in the corpus at least. Perhaps that is because
+this attribute has only been observed as @code{false}.
+@end defvr
+
+@defvr {Attribute} scientific
+This attribute controls when and whether the number is formatted in
+scientific notation. It takes the following values:
+
+@table @code
+@item onlyForSmall
+Use scientific notation only when the number's magnitude is smaller
+than the value of the @code{small} attribute.
+
+@item whenNeeded
+Use scientific notation when the number will not otherwise fit in the
+available space.
+
+@item true
+Always use scientific notation. Not observed in the corpus.
+
+@item false
+Never use scientific notation. A number that won't otherwise fit will
+be replaced by an error indication (see the @code{errorCharacter}
+attribute). Not observed in the corpus.
+@end table
+@end defvr
+
+@defvr {Optional} small
+Only present when the @code{scientific} attribute is
+@code{onlyForSmall}, this is a numeric magnitude below which the
+number will be formatted in scientific notation. The values @code{0}
+and @code{0.0001} have been observed. The value @code{0} seems like a
+pathological choice, since no real number has a magnitude less than 0;
+perhaps in practice such a choice is equivalent to setting
+@code{scientific} to @code{false}.
+@end defvr
+
+@defvr {Optional} prefix
+@defvrx {Optional} suffix
+Specifies a prefix or a suffix to apply to the formatted number. Only
+@code{suffix} has been observed, with value @samp{%}.
+@end defvr
+
+@subsubheading String Attributes
+
+These attributes are used for formats when @code{baseFormat} is
+@code{string}.
+
+@defvr {Attribute} tryStringsAsNumbers
+When this is @code{true}, it is supposed to indicate that string
+values should be parsed as numbers and then displayed according to
+numeric formatting rules. However, in the corpus it is always
+@code{false}.
+@end defvr