Distinguish between METAR and SPECI

[Auberginn]

Hello,

I'm am trying to retrieve the proper hourly weather observations data using the /stations/{stationId}/observations API link request. When I retrieve the result, I see METAR and SPECI observations ordered by descending timestamp, but I can't find a way to distinguish them (METAR or SPECI), otherwise then checking the regular frequency of the timestamps to identify the corresponding minute of the METAR publications. Is there a better/proper/ way to do this?

METAR (based on the more frequently seen publication minute in the API response)
"station": "https://api.weather.gov/stations/KALB",
"timestamp": "2020-11-26T18:51:00+00:00",
"rawMessage": "KALB 261851Z 17004KT 9SM FEW005 BKN055 OVC070 11/11 A2990 RMK AO2 SLP127 OCNL BINOVC T01110111"

SPECI
"station": "https://api.weather.gov/stations/KALB",
"timestamp": "2020-11-26T18:14:00+00:00",
"rawMessage": "KALB 261814Z 17006KT 7SM VCFG FEW001 SCT005 OVC055 11/11 A2991 RMK AO2 VCFG E T01060106"

Thanks,

Charles