I prefer &lt;angle brackets&gt;, but these brake in some places.<p>RFCs have some useful info.<p><a href="https:&#x2F;&#x2F;tools.ietf.org&#x2F;html&#x2F;rfc3986" rel="nofollow">https:&#x2F;&#x2F;tools.ietf.org&#x2F;html&#x2F;rfc3986</a> Appendix C<p>Appendix C.  Delimiting a URI in Context<p><pre><code>   URIs are often transmitted through formats that do not provide a
   clear context for their interpretation.  For example, there are many
   occasions when a URI is included in plain text; examples include text
   sent in email, USENET news, and on printed paper.  In such cases, it
   is important to be able to delimit the URI from the rest of the text,
   and in particular from punctuation marks that might be mistaken for
   part of the URI.

   In practice, URIs are delimited in a variety of ways, but usually
   within double-quotes &quot;http:&#x2F;&#x2F;example.com&#x2F;&quot;, angle brackets
   &lt;http:&#x2F;&#x2F;example.com&#x2F;&gt;, or just by using whitespace:


      http:&#x2F;&#x2F;example.com&#x2F;

   These wrappers do not form part of the URI.

   In some cases, extra whitespace (spaces, line-breaks, tabs, etc.) may
   have to be added to break a long URI across lines.  The whitespace
   should be ignored when the URI is extracted.

   No whitespace should be introduced after a hyphen (&quot;-&quot;) character.
   Because some typesetters and printers may (erroneously) introduce a
   hyphen at the end of line when breaking it, the interpreter of a URI
   containing a line break immediately after a hyphen should ignore all
   whitespace around the line break and should be aware that the hyphen
   may or may not actually be part of the URI.

   Using &lt;&gt; angle brackets around each URI is especially recommended as
   a delimiting style for a reference that contains embedded whitespace.

   The prefix &quot;URL:&quot; (with or without a trailing space) was formerly
   recommended as a way to help distinguish a URI from other bracketed
   designators, though it is not commonly used in practice and is no
   longer recommended.

   For robustness, software that accepts user-typed URI should attempt
   to recognize and strip both delimiters and embedded whitespace.

   For example, the text

      Yes, Jim, I found it under &quot;http:&#x2F;&#x2F;www.w3.org&#x2F;Addressing&#x2F;&quot;,
      but you can probably pick it up from &lt;ftp:&#x2F;&#x2F;foo.example.
      com&#x2F;rfc&#x2F;&gt;.  Note the warning in &lt;http:&#x2F;&#x2F;www.ics.uci.edu&#x2F;pub&#x2F;
      ietf&#x2F;uri&#x2F;historical.html#WARNING&gt;.

   contains the URI references

      http:&#x2F;&#x2F;www.w3.org&#x2F;Addressing&#x2F;
      ftp:&#x2F;&#x2F;foo.example.com&#x2F;rfc&#x2F;
      http:&#x2F;&#x2F;www.ics.uci.edu&#x2F;pub&#x2F;ietf&#x2F;uri&#x2F;historical.html#WARNING</code></pre>