Hillary Clinton’s confirmation remarks as US Secretary of State may have dwelt too briefly on Africa, but her office’s recent use of Presidential Proclamation 7750 shows high-level interest in supporting Kenya’s war on corruption.

We wish it were clear, however, just what the US has done and why. Proclamation 7750 (better known as the Kleptocracy Initiative travel ban), issued by George W Bush in January 2004, has been used to prohibit corrupt officials from entering the US. At least 13 Kenyan public officials and their families are believed to have had travel restrictions placed on them under this directive. However, who they are and what they did remains a matter of conjecture.

With the addition of the latest name to the ‘no-fly’ list, the US embassy has once again invoked privacy protection regulations to explain its refusal to name the individual. But a look at the Federal Register (similar to the Kenya Gazette) shows other proclamations list visa restrictions for identifiable groups. It is useful to know, for instance, State officials from Sudan and Zimbabwe can’t travel. But what use are anonymous corruption bans apart from exerting private pressure?

The 7750 bans are concerned with public corruption that has "serious adverse effects on American national interests". As this includes the activities of US businesses, there is a danger of bans being a political tool to advance commercial interests. To avoid such suspicion, the US should at least provide details of the acts of corruption that it targets.