These references haven't been visible for years. Related to: - https://github.com/gohugoio/gohugoioTheme/issues/24 - https://github.com/gohugoio/gohugoioTheme/pull/216
Just like in the Go programming language, Go and Hugo templates make heavy use of range to iterate over a map, array or slice. Other templating languages use a foreach for the equivalent functionality.
range
range is fundamental to templating in Hugo. (See the Introduction to Hugo Templates for more examples.)