As a defensive structure the dyke has no obvious military value and its erratic route militates against it being a practical political boundary.

[2] In 1824 the Deil's Dyke is first recorded in print by Chalmers in his 'Caledonia' where he credits Joseph Train, amongst others, for the description of what survived at the time and for recognising its significance, ambiguous as that remains.

[6] Originally it was said to run from Loch Ryan to the shores of the inner Solway and was a boundary between the Picts and the Britons of Strathclyde with a defensive palisade, watchtowers and forts however this has been shown to be incorrect as a number of the linear features included were shown to be head-dykes and other unrelated landscape features.

[6] No one single feudal land holder is known to have controlled such a large area so its construction as an estate boundary is implausible, but a mediaeval head-dyke function or a deer hay wind function or a hunting forest demarcation fits the evidence better.

It has been noted that a considerable number of similar earthworks exist in the vicinity of the dyke making interpretation a challenge.

[7] In a number of places along its route it has been utilised and modified or possibly originally built as a head-dyke which physically separated the arable lower lying land from the upland pastures which were grazed by sheep and cattle which would have otherwise eaten any arable crops.

The terms 'in-field' and 'out-field' are sometimes applied[12] and both are clearly marked on the landscape as green lush vegetation on lower lying land against the more complex colours of bare rock, heather, bracken, etc.

[12] The often erratic route may be explained by the need to enclose as much good quality arable land as possible.

[14] The course of the Deil's Dyke is not noticeably associated with the many defensive features that exist in Nithsdale, such as Iron Age forts, medieval mottes, etc.

The Catrail in Roxburghshire, southern Scotland, has a number of similarities with the Deil's Dyke and consists of a bank and a ditch and runs for 11.5 mi (18.5 km).

c. NS 8020 0601: In 1978 this section had a bank that on the north or downhill side enclosed an area of rig and furrow and lies close to the Hawkcleuch Burn.

v. NS 8404 0526: The dyke is thought to have started on the left bank of the Burnsands Burn in the area of its confluence with the River Nith.

"[17] This description would be relevant in terms of the termination of a detached section of the Deil's Dyke in a wooded area.

[25][26] A section of the dyke here is recorded by the RCAHMS in 1920 as having a foundation of large stones that indicate a width of seven feet.