The colored arrows above the cargo and AbR modules represent the directionality of the transcription flow of that element
The figure sketches the expanded rules for naming each of the 4 positions available for composing a complete SEVA code. The first position identifies the antibiotic resistance. The second position is the origin of replication (a sole numeric code 1 to 9 and then a capital letter is added). In case of either variants or addition(s) of either the antibiotic marker or a second replication origin, a lower case letter is then inserted next. The third position is the cargo, which can be mono-function (named 1 to n) or variants/multi-function thereof (number followed by a capital letter). Finally, the fourth position is for the gadgets, which are designated by lowercase Greek letters (α to ω). For instance; pSEVA237M means a KmR plasmid with a pBBR1 origin of replication and a promoterless msfGFP reporter (mono-function). pSEVA2313R means KmR, pBBR1 origin and a PEM7–>mCherry cargo (bi-function). pSEVA 2a2b8Rα means KmR plasmid selectable in Gram-positive hosts with a double RK2-SCP2* replication origin, a bi-functional cargo xylS-Pm–> mCherry and a hok-sok gadget.