Exact Filename Convention

Instruction filenames must contain only alphanumeric characters, dots, underscores, and dashes — matching the pattern ^[A-Za-z0-9._-]+$. This prevents encoding issues, shell escaping problems, and path resolution failures across platforms.

Antipatterns

• Spaces in filenames like my rules.md — spaces break shell commands and require quoting in every context.
• Special characters like [email protected] or check(1).yml — characters outside the allowed set cause path resolution failures on some platforms.
• Unicode or accented characters like regles.md — the pattern allows only ASCII alphanumerics, dots, underscores, and dashes.

Pass / Fail

Pass

CLAUDE.md
.cursorrules
my-config_v2.yml
SKILL.md

Fail

my rules.md
config (copy).yml
[email protected]

Limitations

Validates the filename against ^[A-Za-z0-9._-]+$. Does not check parent directory names — a file at BAD NAME/valid-file.md would pass.