|Name||Rapid Dots (OLX)|
S05a was operated by Czechoslovak State Security under an ITU-registered callsign "OLX" (though officially assigned to ČTK, the press agency) and allocated frequencies. The language was Czech. Replaced in early 1990s by S05b.
|Series of rapid beeps||061|
|Repeated for 5 minutes||Repeated for 2 minutes|
|Series of rapid beeps||424||73||57966 85288 30427 ...||Opakuji||73||57966 85288 30427 ...||Konec|
|3-figure ID||Amount of 5-figure groups in the message||5-figure single groups||"[I] Repeat"||Amount of 5-figure groups in the message||5-figure single groups||"End"|
|Played for 5 minutes||Repeated for 5 minutes|