The most widely used system for classifying Old English prosodic patterns is based on that developed by Eduard Sievers and extended by Alan Joseph Bliss.
Another popular system is that of Geoffrey Russom, which is predicated on a theory of meter involving two metrical feet per verse.
After applying the appropriate arsis or thesis to a line, we look at the rhythm that the markings make and assign a type-line, or foot, to the half-line.
Sievers created type-lines based on the metrical patterns that he saw in Old English poetry, and named them in alphabetical order according to the most frequently used.
Another metrical system was put forward by John C. Pope in which rhythmic stress is assigned using musical patterns.
As mentioned above, the fact that the structure of Old English poetry is so rigid and formulaic is an incredibly useful tool for extrapolating meaning from damaged or poorly transcribed manuscripts.
For example, the first part of the “Finnsburg Fragment” is missing, but by using these basic metric ideas, at what some of the words of the last half-line can be guessed: oððe hwæþer ðǣra hyssa * * * * * or whether of the young men * * * * * First, the most important word in the first half-line is looked at, "hyssa" or "young men."
A knowledge of paleography and the scribe’s penmanship is also useful; words that would be too long or too short to make something fit can be ruled out.