bigcouch/cloudant sequencese are dddd-sssssss (digit, string), going with the string "0" marks itself as the first checkpoint.  However, on other sequences, if you know that there's some sequence 12345-sadfsadflsjafkalsfjsdf, you can't just do "12344" to go "latest - 1" on a sequence. or "12345" to go to the next one.