We support to exclude coverage from some regions via the GCOVR_EXCL_... markers. In my opinion these should only be used with care and if really necessary. To judge the places where the markers are used it would be nice to include them in some way to the overall reports. I could imagine some ways (for e.g. the HTML report):

a) We have another column which shows how many lines are skipped. Then we can quickly judge how many lines are not considered?
b) We add an additional page which lists all places where we exclude coverage?
c) We mark the excluded regions with a special color in the detailed coverage report, currently they are just not marked at all.