IMP XXXXII COS XVII P P (type III / II, B, 3 dots on reverse) (441 / 450)
Bust of Theodosius II facing, cuirassed, wearing a helmet with crest and a pearl diadem. Holding a spear passing behind his head with the right hand and a decorated shield with a horseman slaying an enemy, with the left hand.
PP Constantinople seated left on a throne, holding a spear with the left hand and a globe surmounted by a cross with the right hand. A shield behind the throne and a star in the field to the left.
Marks
Photo of a coin sold on 18 January /2017 by Classical Numismatic Group, Electronic Auction 389, lot 813, link to the sale: https://www.acsearch.info/search.html?id=3673902, link to their website: https://www.cngcoins.com/.
Variant without a dot on the obverse and three dots on the reverse located after XVII, the first and the last P of P P. COMOB mark. Reverse of type III (legend with dots) and design of type II, shield of type B.
This coin shares the same reverse die as the specimen sold on 25 September 2021 by Fritz Rudolf Künker, Auction 351, lot 564, link to the sale: https://www.acsearch.info/search.html?id=8544028. This reverse die gives the impression of seeing two dots after the last P, It is actually the dot that is part of the shield design. A feature also found on a coin sold on 18 November 2013 by Numismatica Ars Classica, Auction 75, lot 380, link to the sale:https://www.acsearch.info/search.html?id=1757593.
Lets note the coin sold on 05 May 2013 by Pegasus Auctions, Auction 2, lot 2173, link to the sale: https://www.acsearch.info/search.html?id=1564410. This coin features a reverse style quite similar to Type I, with stiff drapery and a triangular-shaped knee. The reverse is of Type II, but the engraving in the areas mentioned reveals a similarity to Type I. Perhaps a die created during the extensive use of Type II dies, alongside some re-use of older Type I dies. The first dot after XVII is erased, but a small mark remains.
The ranking follows the positional order of the dots on the reverse (before the first or second... abbreviation or date). Each difference in the position of the dots is classified as "var" if the same "var" exists with two different officina letters, So the first one will be classified as "var" and the second coin as "var, a" with the small "a" indicating the next officina letter. Thus we have, for example, the AYC #39 var with the officina 
and the AYC #39 var, a with the officina S, the two numbers having exactly the same dots positions in the legend.
It is noticeable that the number of coins with three dots on the reverse (regardless of position or association with dots on the obverse) is much higher than that of coins with one or two dots. The number of specimens increases with each new dot added, when reaching the 6 dots these coins outnumber the combined total of all other coins ranging from 1 to 5 dots.
On many coins (regardless of the number of dots), there is a sort of dark dot located between the two Ps or after the last one (like on this coin referenced here). If one of the dots is unmistakably present after one of the Ps, the other letter often shows another dark dot. Is it a case of a clogged die revealing a tiny remnant that looks like a sort of smudge due to the lighting in the photo? This also applies to other spots in front of other letters (though this is less common). It could just as well be a matter of micro-cracks in the die like those seen on the obverse but the location of these small details on the reverse is peculiar, as they are situated between the letters.
I am listing here a coin that appears to have the same number and placement of dots on the reverse, but which shows numerous breaks that create the impression of additional dots being present. This illustrates the comment above regarding the dot count on this coinage. Coin sold on 10 March 2009 by Gorny & Mosch Giessener Münzhandlung, Auction 176, lot 2652, link to the sale: https://www.acsearch.info/search.html?id=589532.
Type III: with the mark CONOB or COMOB (CONOB here). Legend punctuation on the reverse. This corresponds to type II of RIC X. Variant A and B are the same as RIC X: A = large, B = smaller, rounder shield. This type blends characteristics of types I and II in terms of design and the position of the legend relative to the shield: Constantinople large or small, helmet flat or not, drapery tight or not natural, legend ending before or at the level of the shield. The likely reuse of old reverse dies (there are already links between obverse dies and coins without reverse dots) consequently mixes the first two types. This mixing of the two types may also demonstrate the high probability that this series with dots on reverse is the last. For each Type III coin, I add the reverse design type after ''/'', thus giving either: ''III / I'' or ''III / II'', designating a Type III reverse with a Type I or II design followed by shield type A or B.