http://comicslate.org use comic folders with number pages 0001...0002... and unpublished Cnav plugin. It has syntax {cnav} and can locate uncommon names for back and forward links, such as {cover<cnav}...{cnav>0001a}...{0001<cnav>0001b}. {cnav-3} used for 001...002 and so on; other number option allowed. On index page {cnav} mean start of comic reading and hasn't "back" part.
Additionally we use these strings in conf/entities.local.conf:
[back] <a href="./index" class="media" accesskey="p"><img src="/lib/plugins/cnav/images/left.png" class="media" title="Back" alt="←" /></a>
[up] <a href="../index" class="media" accesskey="i"><img src="/lib/plugins/cnav/images/up.png" class="media" title="Upfolder" alt="↑" /></a>