This patch was discussed with Ton and should likely be examined by Campbell regarding his intent via the Ctrl-L patch for View3D.

Campbell added the marker to scene via the View3D, but it doesn't seem to work as the marker requires a timeline / animation pane view for standard timeline markers. Not sure if armature style markers work with Ctrl-L. Ton cited that it is also a typo, as the Markers would never be linked but rather copied. In following the language, it should likely follow "Duplicate".

This patch addresses the following issues:

1) There was no method to copy timeline / animation markers to another Scene.
2) The Marker menu was inconsistent for the Timeline view. The other four views (VSE, NLA, Graph, and Dopesheet) each include a Marker menu, but the Timeline did not. To enhance the internal mental model consistency, the Timeline view should reflect the model reinforced by the other views.

The following items should be considered:

1) Provide a means to import / export markers from another .blend file. This would make it easier to share timing and planning from one Blender file to another.
2) Design a method to share common menu / UI interface elements between editor spaces. This would assure an internal mental model consistency and make it significantly easier to be certain a single element makes it out to all touch points.

The patch could be further optimized by:

1) Disabling as per the other operators when markers are not selected.
2) Creating an internal ordering within the menus. The script attempts to do so, but the final UI layout seems to be overridden by an underlying hierarchy.