How can you tell if a METAR or SPECI report is a corrected report?

A METAR or SPECI report is identified as a corrected report if it includes the modifier "COR." The presence of this modifier indicates that the report has been amended or corrected from a previous version. This is important for users of METARs and SPECIs, as it ensures that they are referencing the most accurate and current information available.

The other options serve different purposes or do not specifically denote a corrected report. For instance, the letter "A" does not signify a correction in the context of METAR or SPECI reporting; it often pertains to other types of data or identifiers associated with the report. A timestamp is included in all METARs and SPECIs to denote when the report was issued, but it does not indicate whether the report is corrected. Lastly, including a TAF reference in a METAR or SPECI report is relevant for context but does not imply that a correction has been made to the report.