Although English is a language used throughout the world, it is not universal. For example in the United Kingdom many words are spelt differently than they would be in the United States. Beyond simple misspellings commonly used phrases can mean completely different things depending upon where you are in the world. The chart below from Ellis Pratt shows, in a comical way, some of these phrases.
For a technical communicator this is an absolute nightmare. A product being launched in the United States and the United Kingdom would need two sets of documentation simply to accommodate the variance in language. These same issues exist even within the United States. Phrases that are common place in the south might sound absolutely foreign to someone from Maine, and they could carry with them a different meaning. The variance in language is something we always need to keep in mind when writing for audiences in different areas.