As she closed the gap, the Australian cruiser requested that "Kormoran" identify herself. Communications were initially attempted with a signal lamp to repeatedly send "NNJ" ("You should make your signal letters"), but those aboard the raider did not understand the uncommonly used signal and did not respond. "Sydney" continued to signal for 30 minutes, after which those aboard the cruiser used flags to send the more common "VH" signal ("You should hoist your signal letters"), while the signal lamp was used to transmit the message in plain language. After another delay, "Kormoran" raised "PKQI"—the call-sign for the Dutch merchant ship "Straat Malakka"—on the triatic stay and hoisted a Dutch merchant ensign. As "Sydney" was approaching from just starboard of "Kormoran"s stern and away, the call-sign was obscured by the raider's funnel: German accounts vary as to if this was to further the illusion of a civilian ship, a ruse to lure "Sydney" closer, or an error on the signaller's part. "Sydney" signalled "Make your signal letters clear", which the signals officer aboard "Kormoran" did by lengthening the halyard and swinging it around to starboard. By 16:35, with "Sydney" away, the malfunctioning engine aboard "Kormoran" was repaired, but Detmers chose to keep it in reserve.