Illinois Request For assessment By Legal Description is a request filed with the county assessor that allows taxpayers to dispute the assessed value of their property. The taxpayer must provide a legal description of the property as well as supporting documentation to substantiate their claim. The county assessor will then review the request and determine the appropriate assessed value. There are two types of Illinois Request For assessment By Legal Description: (1) a Form PTAX-341, which is used to contest the assessed value of a single parcel; and (2) a Form PTAX-341A, which is used to contest the assessed value of multiple parcels.