Support for Sub-TLVs within VSA TLVs

Hi All, I am trying to make a dictionary for Wimax attributes(defined by Wimax forum/NWG). Few of the attributes they defined have sub-attributes. Format for one such attribute is given below: RadiusType = 26 Length Value -->Wimax Type = 10 -->Length -->Sub-type = 1 or 2 or 3 ---->Length ---->Value Does Freeradius have support for Sub-TLVs inside VSA TLVs today? If yes, can someone please give me an example of one such entry in dictionary. If Freeradius does not currently support sub-attributes, is there a plan to support this in future? Thanks in advance Santosh