How do I install the Special Chars skill?

Run npx skillmds@latest add thedaviddias/special-chars in your terminal (requires Node.js), paste this page's agent-chat prompt into Claude, Cursor, or any MCP-connected agent, or download the SKILL.md file and copy it into your agent's skills directory.

Is Special Chars safe to use?

This skill has not completed SkillMD's automated safety review yet. SkillMD never runs a skill's scripts for you; review the SKILL.md before installing.

Which AI agents work with Special Chars?

This skill is tagged as working with Claude Code, Claude.ai, OpenAI Codex. SKILL.md is an open format, so most agents that read a skills directory can load it too.

Is Special Chars free to use?

Yes. Installing skills from SkillMD is free, and the skill stays under its author's original license.

Who published Special Chars?

thedaviddias (@thedaviddias) published this skill. Their other Agent Skills are listed on their SkillMD profile.

Special Chars by thedaviddias — Agent Skill

Name: Special Chars
Author: thedaviddias

File contents

URL Special Characters

Special characters in URL paths cause inconsistent crawling, broken links when shared, and canonicalization failures when different systems encode them differently.

Quick Reference

URL paths should contain only unreserved characters: A-Z, a-z, 0-9, -, _, ., ~
Spaces must be encoded as %20 (not +, which is query-string syntax)
Characters like #, ?, &, = have reserved meaning in URLs and must be percent-encoded in path segments
Non-ASCII characters (accented letters, CJK) should be percent-encoded in URLs, though modern browsers decode them for display

Check

Scan all crawled URL paths for characters outside [A-Za-z0-9\-_./~]. Flag URLs containing spaces (%20 or literal), special symbols (#, ?, &, =, + in paths), or unencoded non-ASCII characters. Check if different encodings of the same URL return separate 200 responses.

Fix

Update the URL generation logic in your CMS or framework to strip or replace special characters. Replace spaces with hyphens. Percent-encode any reserved characters that must appear in paths. Set up redirects from problematic old URLs to clean new slugs.

Explain

Explain the difference between reserved and unreserved characters in RFC 3986, how browsers and crawlers handle inconsistent percent-encoding, and why special characters in paths create duplicate content risks.

Code Review

Review metadata generation, rendered HTML, structured data, and response headers related to URL Special Characters. Flag exact routes or templates where search-facing output violates the rule, and describe how to verify the final page output.

For full implementation details, code examples, and framework-specific guidance, see references/rule.md.

Rule page: https://frontendchecklist.io/en/rules/seo/special-chars

---name: special-charsdescription: Use when applies to any site with user-generated slugs, CMS-generated URLs, or content in non-English languages. Use when auditing URLs for crawl errors or canonicalization issues.---# URL Special CharactersSpecial characters in URL paths cause inconsistent crawling, broken links when shared, and canonicalization failures when different systems encode them differently.## Quick Reference- URL paths should contain only unreserved characters: A-Z, a-z, 0-9, `-`, `_`, `.`, `~`- Spaces must be encoded as `%20` (not `+`, which is query-string syntax)- Characters like `#`, `?`, `&`, `=` have reserved meaning in URLs and must be percent-encoded in path segments- Non-ASCII characters (accented letters, CJK) should be percent-encoded in URLs, though modern browsers decode them for display## CheckScan all crawled URL paths for characters outside `[A-Za-z0-9\-_./~]`. Flag URLs containing spaces (`%20` or literal), special symbols (`#`, `?`, `&`, `=`, `+` in paths), or unencoded non-ASCII characters. Check if different encodings of the same URL return separate 200 responses.## FixUpdate the URL generation logic in your CMS or framework to strip or replace special characters. Replace spaces with hyphens. Percent-encode any reserved characters that must appear in paths. Set up redirects from problematic old URLs to clean new slugs.## ExplainExplain the difference between reserved and unreserved characters in RFC 3986, how browsers and crawlers handle inconsistent percent-encoding, and why special characters in paths create duplicate content risks.## Code ReviewReview metadata generation, rendered HTML, structured data, and response headers related to URL Special Characters. Flag exact routes or templates where search-facing output violates the rule, and describe how to verify the final page output.---For full implementation details, code examples, and framework-specific guidance,see `references/rule.md`.Rule page: https://frontendchecklist.io/en/rules/seo/special-chars

Frequently asked questions

Special Chars