Seniority of senators
For certain purposes, such as the allocation of accommodation in Parliament House, the seniority of senators is significant. A list of a senators’ seniority is maintained by the Usher of the Black Rod. Senators’ seniority is determined in accordance with their period of continuous service as senators.
The senator with the longest continuous period of service used to be referred to as the “Father of the Senate”, but this title is now seldom referred to or used (as no woman senator has ever been in this situation, it is not clear what the title would be in that circumstance).