1. A method, comprising: at a computer comprising a computer program to implement processing operations: receiving data related to content of a target; filtering the data to locate a target term; accessing one or more tables in a repository, the one or more tables comprising entries with a substitution unit corresponding to the target term, the entries arranged according to a prioritized scheme that defines a position for the substitution unit in the tables; and generating an output comprising data that represents the substitution unit to be utilized by a text-to-speech generator to generate spoken content, wherein the position of the substitution unit in the one or more tables is assigned based on a specificity characteristic that describes the relative inclusivity of the substitution unit as compared to other substitution units in the one or more tables.