The Mother Doctrine was a Terran Hegemony government policy restricting the dissemination of certain advanced technologies outside its borders to retain the Hegemony's technological advantage.
Brief History of Mother Doctrine
Formed during the reign of Hegemony Director-General Michael Cameron, the Hegemony Research Alliance Department imposed centralized controls over wide-range of government research projects, but also massively increased the funding to such projects, triggering a ongoing wave of technological advances.  This technological boom would continue during the reign of his daughter and successor Margaret Cameron, with the Hegemony having made great strides in advancing both civilian and military technology and raising the standard of living for all within its borders.
This situation caused friction with the other less advanced but more resource rich Great Houses surrounding the Hegemony and prompted many in the government to consider limiting the spread of such technology to the other realms to allow it to retain its technological advantage against them. While in her heart Lady Marget believed sharing the Hegemony's advances would honor the beliefs of her father and Hegemony founder James McKenna to see the Hegemony as the beacon of Human civilization, the increasing tensions between the other interstellar governments and her realm finally forced her to agree.
In 2380 Lady Margret imposed would be later referred to as the Mother Doctrine, creating an Official List of Sensitive and Secret Technologies which were strictly prohibited from export, with many pieces of military equipment figuring prominently upon it.  While the HRAD was originally formed specifically to coordinate government research, under the Mother Doctrine Margret had the centers expanded to also cover commercial research projects. The benefit of this was to enhance the exchange of information between the government and industry, while giving the Hegemony government first hand access to determine which commercial projects was too advanced for exportation and to enter them on to the Official List of Sensitive and Secret Technologies. Some firms who felt the government was unduly restrictive and derisively calling it the Cameron Blacklist at first tried to ignore the restrictions, but governmental seizure of their assets and treason charges against their corporate executives effectively ended the bulk of the resistance to the Mother Doctrine. 
Despite its efforts the Hegemony government recognized that some degree of leakage would occur and even accepted the occasional loss, content that its continuing advances would make such losses quickly obsolete. The government itself also allowed the release of certain closely held secrets, most notably terraforming and other related technologies, serving as the carrot to entice the surrounding realms to agree to Margret's Jointly-Owned Worlds proposal, giving the resource depleted Hegemony access to new desperately needed sources of raw resources.
- Star League, p. 20 "Rise of the Camerons - Government and Science"
- Star League, p. 23, "Lady Margaret Cameron"
- Star League, p. 159, "Economy of the Terran Hegemony"