STNR = Stop Trying Nobody responds
Seriously though i'm surprised no one could tell you what it means - it's an ICAO abbreviation meaning Stationary.
For example:
"SYNOPSIS...STNR FNT WL CONT DURG FCST PD FROM NRN PTN ATLC SWRN
NEW YORK FIR SWWD THRU FL STRAITS TO NERN TIP YUCATAN PEN. WDLY
SCT TSRA EXP EITHER SIDE OF FNT MAINLY FROM NRN BAHAMAS"
Don't you just love them ICAO Acronyms