OpenRoads Level Definitions-Modeled elements vs drafted elements

Just looking to get an idea on what others are doing in regards to OpenRoads modeling elements vs elements that aren't being modeled.  Maybe there is a best practice for this?

Opinions on defining levels that are specific for "modeled" graphics/elements created from OpenRoads.  i.e. m_TOPO-CUTT, m_TOPO-FILL, m_ROAD-EDGE, m_SHLDR-EDGE, m_STORM-PIPE, m_STORM-INLT, etc... vs using the defined corporate levels of C-TOPO-CUTT, C-TOPO-FILL, etc...  Is there a real good reason to separate them?

My thoughts are that we would replace the "C-" prefix with the prefix "m_".  The "m_" signifies that these elements are modeled from software and not a "drafted" element.

Your comments are greatly appreciated.

Chuck