When they refer to Swisss typography, they're likely referring to the International Typographic Style, which is also known as the Swiss Style (it's on Wikipedia). It's a style of graphic design. It typically uses a Grotesque sans serif font, like Helvetica or Univers (as opposed to a humanist sans serif).
Closing the loop a bit, Helvetica is the second word of the Latin name of Switzerland (Confoederatio Helvetica). It's why the ISO 3166 code for the country is .ch.
