Final answer:
The term 'Acting' designates a temporary official, such as when the Vice President becomes Acting President under the 25th Amendment.
Step-by-step explanation:
When someone is temporarily fulfilling the role of an official, the title "Acting" is used to signify their interim position. Specifically, in instances involving presidential succession, the 25th Amendment outlines the process where the Vice President becomes the Acting President if the President declares an inability to perform presidential duties or is declared unable by the Vice President and a majority of principal officers. This appointment is signified by the term “Acting” appearing beneath their name in official correspondence.
This process, enshrined in the amendment, safeguards the continuity of executive authority while addressing the need for temporary leadership adjustments in the highest echelons of government.