- Neat Clean Modern Styling - no white edge pixels as on many on the phpbb gif's, so work well on a variety of backgrounds
- Fast and efficient - one http request for all font icons in one package
- Scalable - work well on high definition screens in the latest laptops and tablets, work well on mobile devices, scale well at large sizes if you want them large as well as small
- Versatile - can be styled with css including colour size etc
- Easy to use - a few lines of code in overall header - and easy to insert into other pages
- Choice - lots of existing icon sets to chose from and it is possible to design your own and import them into an existing font icon set
I am currently using Font Awesome with good results, as many of the icons in that set are very similar to many of the small icons currently used in phpbb.
But there is also IcoMoon app which allows you to chose from 1800+ free icons (including the Font Awesome set), maintain and chose an icon set with only the icons you actually want to use, import your own custom icons, as vectors (svg), save an icon set for future editing (all client side processes, some features currently available in Chrome).
If I can get these working in phpbb, with great results, with my limited skill set and knowledge then anyone should be able to.