Location Markers can be create at any position in a session.
To create a location marker using the Location Marker ruler at the top of the Timeline right click anywhere on the ruler and select New location marker, to move the marker to the current Playhead location right click on the new marker and select Move Mark to Playhead
See section on Working with the Range & Marks for how to create a Location Mark at the current playhead location.
To create a Location Marker at the current playhead location press Enter on the numeric keypad.
To create a Location Marker at the current playhead location select the Transport pulldown menu then Markers then select Add Mark from Playhead.
To create a Location Marker at a specific location in the Timeline, set the playhead to the desired location and press Enter on the numeric keypad.
Alternatively, a mark can be set to a specific location by using the Ranges & Marks tab, using either the PH button to move a mark to the current playhead location or the clock to set a specific location manually.
+ Location Markers appear in the Locations ruler at the top + of the timeline. The begin and end markers appear + automatically, but you can create custom markers at any position in a + session. +
++ To add a marker at the current playhead position, press + Num-↵ (the Enter key on the numeric keypad). + Alternatively, use Transport > Markers > Add + Mark from Playhead. +
++ To add a marker at an arbitrary location on the timeline, + navigate to the desired position, right-click on the Locations ruler and + select New Location Marker. + You can also go to the Editor list, click New + Marker and use the clock widget to set its position. +
++ For details see + Ranges & Marks + List + and Using + Ardour Clock Displays. +