Not the best example. The lack of quotes around file.scr is an extra-giant-huge hint that OPEN does some parsing, and therefore you should check the docs before using it in a definition (actually it is so very likely that it "won't work" in a definition that you won't even bother checking the docs).

Example aside, this type of word is usually used in a DSL-y way and with parsimony. Confusing uses are to be filed in the misuse/abuse category.