What is NOT a reason for issuing a yellow card?

Issuing a yellow card is a disciplinary action taken by the referee to caution a player for certain types of misconduct during a match. While delaying the restart of play, engaging in unsporting behavior, and showing dissent by word or action are all offenses that warrant a yellow card, allowing excessive substitutions does not fall into this category.

In regulated play, there are specific rules governing the number of substitutions a team may make, and exceeding that limit typically results in a more formal action, such as the disqualification of the illicitly substituted player or other administrative consequences rather than a caution in the form of a yellow card. Thus, excessive substitutions do not fit the criteria for issuing a yellow card, making it the correct answer to the question regarding what is not a reason for showing this caution.