The government is considering giving Emperor Akihito the title of “joko,” an abbreviation of “daijo tenno,” meaning retired sovereign, should he abdicate, sources said Thursday.

To avoid powers being split between the Emperor, if he abdicates, and his successor, an advisory panel to the government of Prime Minister Shinzo Abe is expected to discuss what official role he could play in the future, according to the sources.

Historically, retired emperors have taken such titles as “daijo tenno” and “joko.” But no emperor has relinquished the throne since Emperor Kokaku in 1817, and the current law on Imperial affairs has no provisions for abdication and so no rules on what a retired emperor should be called.

Experts who presented their views on 83-year-old Emperor Akihito’s possible abdication to the government panel suggested giving him as his post-abdication title either “zen tenno” or “moto tenno,” both meaning former emperors but the former describing an immediate predecessor.

Because some retired emperors who assumed the title “joko” historically continued to wield power, some experts have expressed reluctance to assign the title to a newly abdicating emperor. But other experts have disagreed, saying the current Emperor is different because he has merely a symbolic status and no political powers under the postwar Constitution.

The government may also announce a new era name for the next Emperor before he assumes the throne, the sources said.

The idea to announce the name of the new era in honor of Crown Prince Naruhito, 56, around half a year ahead of his accession is aimed at curbing the impact of the change by giving people time to prepare, the sources said.

An era name is declared for the reign of each emperor.

By making the era name public in advance, businesses and government officials would also have enough time to make adjustments such as for calendars and official documents, the sources said.

The government is also eyeing the possibility that the Emperor step down on the last day of 2018, ending the 30-year Heisei Era.

The current era of Heisei, meaning “achieving peace,” commenced on Jan. 8, 1989, a day after Emperor Hirohito, posthumously known as Emperor Showa, passed away.

But the preceding names of Showa, which means “enlightenment and harmony,” as well as Taisho, meaning “great righteousness,” came into effect on the day of each emperor’s accession to the throne.

Abe’s government is considering formulating an ordinance to enable the use of the new era name from the beginning of 2019 and upon the new Emperor’s enthronement, the sources said.

The government has been debating the 83-year-old Emperor’s abdication after he suggested in a rare public video message in August that he was concerned he may one day become unable to sufficiently perform his duties due to failing health.

Advisory panel members are scheduled to release a mid-term report on Jan. 23 ahead of further discussions on the Emperor’s title, status and roles after an abdication. The ruling and opposition parties are also discussing the matter.

The group plans to assess the pros and cons of the situation, including ways to alleviate the aged Emperor’s burden from duties, panel member Takashi Mikuriya said after a meeting Wednesday at the Prime Minister’s Office.

The panel, chaired by Takashi Imai, honorary chairman of the Japan Business Federation, is expected to present its final proposal in spring.

“It’s important to deepen the understanding of the people on the topic by presenting the issues and challenges in an easily understood manner,” Mikuriya, a professor emeritus of political science at the University of Tokyo, said in explaining the aim of the upcoming report.