There are hundreds of icons in Tiki. Right now, jpeg/png/gif. The opportunity is to move them progressively to a vector format. This permits scaling, styling, saving bandwidth, etc.
There are 2 options: SVG vs fonts
It would be a shame to maintain both if there is one that could address the needs. It would be a shame to invest migration time in one of the solutions only to do the work in double later if a change is decided.
Feeling is that Tiki should:
svg -> No Unnecessary HTTP Requests
I have mainly heard about possible issues in respect of browser compatibility towards SVG, but I did not find (with a very! limited time on research) any SVG icon sets for possible integration. So no icon set (and thus no check for licence yet at all).
Below I added the (mostly free and imho mostly LGPL compatible) licences for the icon FONTs mentioned above.
http://www.webhostinghub.com/glyphs/ shows an example how to possibly achieve switchable "icon-sets", as they use the Bootstrap Glyphicon-Halfling names for their icons.
Finally the PNG fallback seems to be sorted in Tiki for FONT, whilst I heve read in the resources of this page, that PNG fallback for SVG seems to be not an easy task <- the last one I might have missunderstood and do further reading.
In my mind, if no serious arguments will be brought up, the actual path to FONT seems the best to do.
Maybe based on names from here (removing "fa-" from the beginning): http://fontawesome.io/cheatsheet
Questions looking for an answer:
{glyph name="plus"} or {fa name="automobile"}