docs(api-and-naming): double underscore wording tweaks

Author: scop

doc/api-and-naming.md

@@ -31,10 +31,10 @@ the box. But there are some, see [configuration](configuration.md).
 Variables and functions whose name contains a double underscore (`__`) anywhere
 in their name are private implementation details, not part of the stable API,
 and not intended to be used outside of their defining context. Internally, the
-double underscores serve as privacy scope markers; there can be more than one
+double underscores serve as privacy scope delimiters; there can be more than one
 pair of them in a name, and functions and variables are intended to reference
 and call other functions and variables within that scope, one level deep,
-sharing a common prefix. For example, a function named `_comp_foo` is allowed
+sharing a common prefix. For example, a function named `_comp_foo` is "allowed"
 to access `_comp_foo__*` where `*` does not contain any double underscores,
 i.e. it should not access `_comp_foo__something__*` despite the common prefix.