I tested this on android beta, but github shows that this is since at least 2014:
4th,5th and 6th value on navbar ATN5 when screen is oriented in portrait mode have no titles - in landscape mode they have "<<<" title which signals that given value corresponds to the airfield mentioned to the left. In portrait mode those values are rearranged so without titles they are meaningless - setting title to something like "B.AlternArr", "Altern1Arr", "Altern2Arr" would reduce confusion.
https://github.com/LK8000/LK8000/blob/master/Common/Source/Draw/LKDrawBottomBar.cpp line 510:
if (ScreenLandscape) {
showunit=LKFormatValue(LK_ALTERN1_ARRIV, true, BufferValue, BufferUnit, BufferTitle); // 100221
_tcscpy(BufferTitle,_T("<<<"));
} else {
showunit=LKFormatValue(LK_BESTALTERN_ARRIV, true, BufferValue, BufferUnit, BufferTitle); // 100221
_tcscpy(BufferTitle,_T(""));
}
Esp when 6.0 manual says: "In the past, “portrait” mode was considered a second choice, after landscape, but now they are both equally good."