 There is a varied list of special topics pertaining to the logical approach to information. This section briefly illustrates just a couple of them, which are important regardless of the particular stance one takes (information as range, as correlation, as code). The first topic is the issue of informational equivalence: when are two structures in the logical approach one is using indistinguishable in terms of the information they are meant to encode, convey, or carry? The second topic concerns the various ways in which the idea of negative information can be understood conceptually, and properly dealt with formally. 