attempt to clarify 'static' unique address guarantees

Author: RalfJung

src/items/static-items.md

@@ -8,7 +8,7 @@
 > [^extern-safety]: The `safe` and `unsafe` function qualifiers are only
 >   allowed semantically within `extern` blocks.
 
-A *static item* is similar to a [constant], except that it represents a precise
+A *static item* is similar to a [constant], except that it represents a unique
 memory location in the program. All references to the static refer to the same
 memory location. Static items have the `static` lifetime, which outlives all
 other lifetimes in a Rust program. Static items do not call [`drop`] at the