[piasa]

Notes from an April 2016 FBI interview with top Clinton aide Huma Abedin, reveal Obama used a pseudonym when emailing Clinton. The bureau said Abedin "expressed her amazement at the president's use of a pseudonym" when emailing with Clinton in late June 2012, around the same time as her boss's trip which included a stop in St. Petersburg.

[piasa]

Looks like it refers to Russia in June 2012:

Hillary Clinton’s trip to Russia - Photos - 1 of 14 ...
https://www.politico.com/gallery/2012/07/hillary-clintons-trip-to-russia/000243-003050...

Secretary of State Hillary Rodham Clinton arrives in St. Petersburg, Russia, on June 28, 2012. Exit Full Screen Mode Previous Photo Next Photo Secretary of State Hillary Rodham Clinton arrives in...
Category:Hillary Rodham Clinton trip to Sweden (June 3, 2012)
https://commons.wikimedia.org/wiki/Category:Hillary_Rodham_Clinton_trip_to_Sweden...

Media in category “Hillary Rodham Clinton trip to Sweden (June 3, 2012)” The following 43 files are in this category, out of 43 total.