The Election Commission (EC) has stressed the importance of all Senate election candidates abiding by election regulations.
The poll body on Thursday outlined seven things that could give a candidate unfair advantages over others.
Any violations of the regulations could result in up to one year in jail and/or a fine of up to 20,000 baht plus a five-year ban from voting, the EC said on Thursday.
The Administrative Court is still considering a complaint filed by some candidates and activists that the rules on self-introduction are overly restrictive. It is not known when it will rule.
Friday is the final day for nationwide candidacy registration for the forthcoming election of new 200 senators. Only candidates will be allowed to vote in the election, and the EC had been hoping to see 100,000 people register. However, only about 35,000 had picked up applications as of Monday.
The first regulation, the EC said, is that all candidates and their assistants are prohibited from mentioning or making any reference to the monarchy when introducing themselves for the election.
Second, candidates who are broadcasters or who work in the media or show businesses are prohibited from exploiting their job as a means of introducing themselves.
Third, candidates are forbidden from giving away or posting in public leaflets to introduce themselves.
Candidates are also prohibited from using harsh words in their self-introduction and verbally instigating social unrest.
They are also prohibited from introducing themselves on TV, radio and print media.
The last rule is that all candidates must not allow political party executives or holders of political positions, including local leaders, to help them with the election.
The EC advised all candidates to carefully study Sections 36 and 70 of the 2018 organic law on the composition of the Senate and the EC regulations pertaining to the self-introduction of candidates.
Between May 10 and 20, a total of 34,847 people asked for applications, with Bangkok recording the highest number at 3,217, followed by the northeastern province of Si Sa Ket (1,834) and the northern province of Chiang Mai (1,594), the EC said.
The fewest applications were seen in Phangnga (60), Bueng Kan (67) and Yala (78).
By region, the Northeast had 10,243 people asking for applications, followed by the South (6,208), North (5,281), East (2,075) and Western region (1,761), the EC said.