Late last week I ran out of application forms so I downloaded the current versions of the forms, printed them, and made a bunch of copies of them. I note that the first page of the application form now asks in question 6 whether or not the course to be replaced is physically usable as certified.
Obviously not all measurers use the newest versions of the form; some have created versions of the form in the software they use that appear different but provide all of the useful information.
Neveretheless the inclusion of this question on the form gives the certifier the information he/she needs to properly populate the "replaces" field on the certificate. If the measurer indicates that this course replaces another, the certifier needs to ask the question.
I'll restate my position on this: If the course has been changed in some way that it can no longer be used as certified, it should be removed from the active list. This should be communicated by the measurer to the certifier, and from the certifier to the course registrar. The last communication should come via the use of the "replaces" form on the certificate. If the Course Registrar ses a course number in the "replaces" field, that should mean that the certifier has verified, through communication with the measurer, that the course identified in that field can no longer be used as certified.
If we do not do this, then I support the removal of the "replaces" field from the certificate. There is simply no reason to include a field on the certificate that is simply ignored (or requires supporting documentation from the certifier forward) as this field apparently does.
I struggle with whether or not a race director should be able to have a course removed from the active list, but lean to saying they should. As courses are mesured and certified because race directors take action to do so, I think they should be able to have their courses removed from the active list at their request. I give a higher priority to their priorities than I do to those of other race directors who might want to use the courses in question.
Additionally, every once in a while there's a case of a course that is inaccurate, most likely because a measurer made a mistake like misidentifying a street or incorrectly stating the direction to a landmark for a start, finish, or turnaround point. I suspect continuing to handles these as special cases works well enough.