Final answer:
Accounting for negative numbers during infix to postfix conversion is particularly relevant in data structures, specifically in relation to stack implementation.
Step-by-step explanation:
Accounting for negative numbers when converting infix to postfix is most relevant in the programming language concept of data structures. While infix and postfix are terms related to expressions primarily dealt with in computer science and mathematics, the specific relevance to programming is in the context of algorithms and data structures, particularly those that involve a stack implementation. This process is fundamental in parsing expressions, which is crucial for evaluating mathematical and logical expressions in many programming scenarios.