This list appears in Hereford, Herefordshire Record Office AL19/2, a register of Hereford bishop Richard de Swinfield, which is a personal register of Bishop Richard de Swinfield. It is 27.3 by 18.4 centimetres in size and contains 204 parchment leaves, in a rather tight binding (Richardson 2016:20).
The dating of this list to 1286 refers to the year in which bishop Richard de Swinfield copied the list into his register and is not intended to suggest the time of its original composition. Its original composition is a more complicated matter. The latest-dated saint is S. Thomas de Cantilupe (d. 1282, but canonised officially in 1320-- after, one should note, Bishop Swinfield copied out the list). Richard de Swinfield been mentored by Cantilupe and thus this inclusion in the relic list is not surprising (Richardson 2016:18). However, the whole of the list is in the simple style of many early lists rather than in litanic groupings, and it begins with a collection of whole bodies--Edward, 'Elvene' (S. Elvan? S. Elwin?), and Ethelmod. Notably, Thomas de Cantilupe is the first saint to appear in this list: his name is clearly recent addition to a rather older list. The collection, at the least, seems mostly older in character. Of note are relics of the grave earth of e.g., Ss. Columba ('Columchille'), Finian, and Brigid, and a bone of S. Winwalloc. There are also the relics or remains of the priest Huna, indicated to have been the 'chaplain' of Æthelthryth ('relquiis Hune sacerdotis, capellani Etheldrithe'). Huna's resting place is given as Thorney in the Old English Secgan be, and his relics are indeed listed in the Thorney relic list: 'Sancti Huni presbiteri' (Rollason 2015:113).