Translating chars into character entity codes, Which characters in the standard ASCII set (1-127) should I translate Options

[Rob Wheeler]

Which characters in the standard ASCII set (1-127) should I translate into character entity codes in my web page?

These are reserved characters which I understand *must* be translated into character entity codes within the coding of a web page. They are used in tags and so the raw characters will mess up your page:

quote ... "
ampersand ... &
less than ... <
greater than ... >

But I'm not sure about these below. Which ones ought I to translate into entity codes in order to ensure the page renders OK? Or perhaps it doesnt matter. Ive searched all over the place but have not been able to find an authoritative answer.

033 ... ! ... exclamation mark
035 ... # ... hash
036 ... $ ... dollar sign
037 ... % ... percent
038 ... & ... ampersand
042 ... * ... asterisk
047 ... / ... forward slash
059 ... ; ... semi-colon
063 ... ? ... question mark
064 ... @ ... AT symbol
091 ... [ ... left/opening bracket
092 ... \ ... back slash
093 ... ] ... right/closing bracket
094 ... ^ ... caret/circumflex
095 ... _ ... underscore
096 ... ` ... backtick
123 ... { ... left/opening brace
124 ... | ... pipe
125 ... } ... right/closing brace
126 ... ~ ... tilde

[pandy]

I think <, > and & are enough, but don't take my word for it.

[Darin McGrew]

As far as HTML is concerned, you should almost always use &amp; for & and you should almost always use &lt; for <

There are times where you can use & and < directly, but given browser quirks and the hassle of remembering the rules, it's easier to use &amp; and &lt; everywhere.

&quot; is really needed only inside quoted attributes. &gt; isn't really needed except to protect from browser quirks.

But then you also have to consider URL encoding. For example, a space in a URL should be encoded as %20