Last year, Niantic introduced a PokéStop nomination feature for Pokémon GO, which initially entered beta for level 40 players in South Korea, Brazil, Mexico, Thailand and Chile. This feature was temporarily disabled due to a technical issue, but it is now back up and running in the aforementioned territories. In addition, the feature is now available in Argentina, Vietnam, Peru, Indonesia, El Salvador, Guatemala, Nicaragua, Costa Rica, Panama, Honduras, Belize, Ecuador, Bolivia, Colombia, Uruguay, Paraguay, Suriname, Venezuela (Bolivarian Republic), Guyana, Taiwan, Denmark, India, Malaysia, Germany, Singapore, Finland, Portugal, the Philippines, Sweden, Turkey, Canada and Belgium. PokéStop nomination is currently limited to level 40 Trainers (child accounts excluded) in the aforementioned regions. Trainers who meet these initial requirements are able to nominate potential PokéStops by submitting photographs and descriptions of the locations. Submissions will be reviewed by experienced users in the Ingress Operation Portal Recon (OPR) project.
Source: @PokemonGoApp