This is about the rewriter. The current 1.1.x code base contains code to support a new way of defining variables, it's in angle brackets, like <var>. This makes it possible to match things like /foo/<var>.txt which isn't possible with the :var syntax as you don't know where the variable name ends.
Although this is an improvement, the rewriter is still very limited. As adding additional features should happen, but the 1.1 release shouldn't delayed any further, I propose to remove this functionality, in order to be able to design a better rewriter, without supporting the legacy <var> notation.