March 2016 - originally issued 3 January 2013 with code M12L the M16L version was first found in early 2016.
12 x 1st class Royal Mail Red booklet , source code MTIL, year code M16L
Printed by Walsall Security Printers
SG GB Concise 2016 catalogue - NEW NUMBER ALLOCATED MF8.
Only non-cylinder booklets available until we get more stock