[5][7] In February 1963, Pengiran Abdul Momin urged local Chinese merchants to set reasonable prices and clearly label them, addressing public concerns over rising costs while assuring that essential goods remained sufficient in the country.

[9] Later that year, on 28 July, he officiated the opening of the adult Malay language class in Lumut and commended the villagers for supporting the government's literacy initiative.

[10] In August, Pengiran Abdul Momin also officiated the opening of the adult religious class for men at Ahmad Tajuddin Malay School in Kuala Belait.

[12] In July, he announced that five villages in the Belait District—Sungai Liang, Lumut, Kuala Balai, Labi, and Bukit Sawat—would soon have community halls, funded with $40,000 under the Rural District Development Plan, to host social gatherings, meetings, and welfare activities.

[14] During the third Belait District Council meeting on 5 June 1965, Pengiran Abdul Momin announced the construction of a rest house in Labi to accommodate government officers on official duties in the area.

[15] As chairman of the Belait District Council meeting in December 1966, Pengiran Abdul Momin provided clarification on the efforts undertaken by the local agricultural office in response to concerns about the Batu 3 experimental farm in Seria.

[5] On 23 July of that year, he became the acting state secretary of Brunei while the incumbent, Taib Besar, was on leave, before resuming his position as district officer of Kuala Belait from 2 September until 1 October.

[18] Pengiran Abdul Momin was appointed as state secretary of Brunei on 25 March 1970, with the sultan's approval[5], and officiated the opening of Anggerek Desa Malay School on 2 July 1970.

[24] On 19 November 1976, he clarified that Bank Darussalam had not been licensed to operate in the country, despite claims in the press, and also welcomed the opening of Kalimantan Finance and Investment Berhad's new branch in Bangar as the area's first financial centre.

[36] Furthermore, Pengiran Abdul Momin inquired about the progress of various road repair projects, questioning whether the allocated budgets for these initiatives in 2005 and 2006 had been fully utilised.

[40] Additionally, he inquired about the progress of the 8th National Development Plan, raising concerns over the lack of clear updates on expenditure status and completed projects.

[18][4] Pengiran Abdul Momin married Datin Dayang Hajah Masnah binti Haji Mohd Yusuf in 1947, and together they had five children—two sons and three daughters.