Boundary symbols

In every reference I can find to ownership of boundaries, a "T" symbol is indicated as the land "owning" the boundary. In the attached 1993 Title plan however, use has been made of "lollipop" type symbols which would appear to indicate boundary ownership.

Is this the case, or do the lollipop symbols mean something else?

Roger - T marks are often used re such matters where personal covenants have been entered into at some point in time re the responsibility for maintaining the boundary
Lollipop symbols are Ordnance Survey markings, not HMLR ones, and have nothing to do with boundary responsibility