« Reply #21 on: Thursday 31 May 18 02:09 BST (UK) »
The 1916 Marriage is Elham Registration District not Elham parish. Elham PRs are held at Canterbury Archives and have been on FindMyPast for a number of years. There is no marriage for Herbert Emery Smith appearing in the parish from a search on FindMyPast. The page number on the BMD index entry is high so could be register office, non-conformist chapel or less likely a parish which hasn't deposited its PRs yet for then. You would need to purchase the marriage certificate to confirm the details.
For information, the Kent PRs due on FindMyPast from later this year are from Kent County Archives at Maidstone and mainly cover the west of the county (but not all as there are three other Archives covering that area too not including parishes now part of London and held at the London Metropolitan Archives).
(KENT) Lingwell, Rayment (BUCKS) Read, Hutchins (SRY) Costin, Westbrook (DOR) Gibbs, Goreing (DUR) Green (ESX) Rudland, Malden, Rouse, Boosey (FIFE) Foulis, Russell (NFK) Johnson, Farthing, Purdy, Barsham (GLOS) Collett, Morris, Freebury, May, Kirkman (HERTS) Winchester, Linford (NORTHANTS) Bird, Brimley, Chater, Wilford, Read, Chapman, Jeys, Marston, Lumley (WILTS) Arden, Whatley, Batson, Gleed, Greenhill (SOM) Coombs, Watkins (RUT) Stafford (BERKS) Sansom, Angel, Young, Stratton, Weeks, Day