RewriteRule relative substitution paths: missing leading slash ambiguity

Goal

To determine how Apache treats RewriteRule substitutions that lack a leading slash and to decide whether a leading slash should be mandated for consistent URL rewriting.

Constraints & Uncertainty

• In Apache 2.4, a substitution without a leading slash is resolved relative to the current directory, often resulting in a 404 if the file is not located there.
• Documentation recommends adding a leading slash for clarity, yet the directive does not enforce it, leaving administrators uncertain about the intended scope.
• Different modules (mod_alias, mod_proxy) may interpret the same relative path differently, creating inconsistent redirect behavior.

Specific Questions

1. Should Apache’s mod_rewrite enforce a leading slash for all substitution strings to avoid ambiguous path resolution?
2. What is the documented behavior for relative substitutions in Apache 2.2 versus 2.4, and how does this affect backward compatibility?
3. Can enabling rewrite logging provide definitive guidance on how Apache resolves relative substitution paths during request processing?