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The grey long dashed line - can't find it on the OS web site.
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Parish Boundary I think - not sure what the 'C' stands for though.
Edit [url= http://www.ordnancesurvey.co.uk/oswebsite/aboutus/reports/misc/abbreviations.html ]Civil Parish Boundary - full list here[/url]
County / Administrative boundary
ETA - Ah yes, didn't see CP - County Parish... an invisible mark of much powerfullness. Can magically shrink bridle paths into footpaths...
Its a huge Bridleway and it means you can ride everywhere within it 😉 I wish we were like the Scots in this respect 🙁
Ahhhh, of course. Thanks guys.
Oooh, Parish Boundaries - often incredibly interesting, they record the earliest delineations (not necessarily relating to church boundaries as the name implies) some of them have been shown to follow ancient earthworks and stones.