Paragraph was missing the “an” before “at-symbol.”

Existing Wording:

Time values are used to represent a time of day, independent of the date. Time value must be known to at least the hour precision, and potentially to the millisecond precision. Time values are specified using at-symbol with a capital T (@T) followed by an ISO-8601 textual representation of the Time value:

Proposed Wording:

Time values are used to represent a time of day, independent of the date. Time value must be known to at least the hour precision, and potentially to the millisecond precision. Time values are specified using an at-symbol with a capital T (@T) followed by an ISO-8601 textual representation of the Time value: