Dear Wikivoyagers,
the Wikivoyage sites currently have string functions for templates enabled. This adds the {{#len:}}, {{#pos:}}, {{#rpos:}}, {{#rsub:}}, {{#count:}}, {{#replace:}}, {{#explode:}}, and {{#urldecode:}} parser functions to MediaWiki markup. These string functions can't be supported on Wikimedia Foundation sites, and templates using them will break after the migration.
Wikimedia Foundation is currently implementing Lua as a scripting language for templates which should offer a better approach in the long run. You can read more about this here: https://www.mediawiki.org/wiki/Lua_scripting
Your help would be appreciated eliminating any existing dependencies on these functions. Wikipedians may also be able to help with conversion to templates not dependent on those functions, and it's worth looking on en.wikipedia.org for templates with the same name or purpose.
Thanks, Erik