diff --git a/README-query.md b/README-query.md
index 9b8d1d6..3417c2a 100644
--- a/README-query.md
+++ b/README-query.md
@@ -17,10 +17,10 @@
 - reg=registration - Direct link to specific aircraft registration(s). Separate multiple with commas. ?icao is preferred as this option takes longer to load.
 - filterAltMin=500 - filter minimum altitute to 500 ft
 - filterAltMax=5000 - filter maximum altitute to 5000 ft
-- filterCallSign=^(UAL|DAL) - filter callsign to United or Delta
+- filterCallSign=^(UAL|DAL) - filter callsign to United or Delta. Take care to escape special characters ( %5E(UAL%7CDAL) in this case).
 - filterType=B738 - filter to aircraft type code B738 aka 737-800
 - filterDescription=L2J - filter aircraft by type description
-- filterIcao=^a - filter icao that start with a
+- filterIcao=^a - filter icao that start with a (escape with %5Ea).
 - filterSources=adsb,uat,adsr,mlat,tisb,modeS - filter planes by source type.
 - filterDbFlag=military,pia,ladd - filter planes by the db flags.
 - sortBy=column - (possible values: icao, flag, flight, registration, aircraft_type, squawk, altitude, speed, vert_rate, distance, track, msgs, seen, rssi, lat, lon, data_source, military, ws, wd