"When a boundary has been settled ... two distinct stages, which have different names not always clearly defined in the literature. These terms are 'delimitation' and 'demarcation'. Cel. Sir Henry McMahon relates how he came to fix upon the terms and how they took root in recent usage.
Finding that precise terms were needed but lacking, he selected these two words, 'delimitation' and 'demarcation', but discovered that the dictionary treated them as synonymous. Consequently he gave them different meanings, which have been adopted. In his own words:

'Delimitation' I have taken to comprise the determination of a boundary line by treaty or otherwise, and its definition in written, verbal terms;

'Demarcation' to comprise the actual laying down of a boundary line on the ground, and its definition by boundary pillars or other similar physical means.
I first made use of these definition in a lecture given to a military institute at Woolwich about 1897, and Lord Curzon paid me the compliment of adopting them in his Romanes Lectures at Oxford in 1907." International Boudaries (1940) by Boggs, S.Whittemore

Volta para "Fronteiras e Limites".