ZTT ELEMENTAL SERIES

With the release of the revisited Liverpool Deluxe Edition, Zang Tumb Tumms Elemental series hits Element 19. Well Doesn't it?
Infact the truth is there have been 20 Elements in this series so far, That is if you go by the Catalogue Numbers of each release to date, when infact there have benn only 17 physical releases! But how can that be?
Below is a list of all the titles released in the series upto this latest Frankie offering.....
01.(Element 00)Various Artists - The ZTT Box Set (Features FGTH)
02.(Element 01)808 State - 808:90
03.(Element 02)808 State - ex:el
04.(Element 03)808 State - Gorgeous
05.(Element 04)808 State - Don Solaris
06.(Element 05)The Buggles - Adventures in Modern Recording
07.(Element 06)Frankie Goes To Hollywood - Welcome To The PleasureDome
08.(Element 07)The Frames - Another Love Song
09.(Element 08)The Frames - Fitzcarraldo
10.(Element 09)The Frames - Dance The Devil
11.(Element 10)Art of Noise - Influence
12.(Element 11)Propaganda - A Secret Wish
13.(Element 12)Various Artists - The Art Of The 12" (Features FGTH)
14.(Element 13)Claudia Brucken - Combined (Features Paul Rutherford)
15.(Element 14)Shades of Rhythm - Extacy Edition
16.(Element 15)Frankie Goes To Hollywood - Liverpool WITHDRAWN
17.(Element 16)Art of Noise - Into Battle
18.(Element 17)?????
19.(Element 18)?????
20.(Element 19)Frankie Goes To Hollywood - Liverpool REVISED
So THE question has to be what are elemnts 17 & 18?
Of course this is not the first time in this series that ZTT have skipped a release and come back to it soon after, on the spine of the latest Frankie release is the teaser Coming next: Blue, Azura, Lemon and Orange.....which leaves us wondering at what the next Elemental Series release will be from thoses Puppet Masters at ZTT.