&gt; Curious. Are there examples of programming languages that allow spaces in identifiers? Obviously, it would need to be designed for that.<p>At least Tcl allows spaces in identifiers, but to &#x27;use&#x27; such identifiers one does have to add a bit of extra &#x27;sugar&#x27; to prevent the code parser from interpreting the spaces as token separators:<p>Example of spaces in a variable name:<p><pre><code>    $ rlwrap tclsh 
    % set &quot;var name with spaces&quot; &quot;contents of the variable&quot;
    contents of the variable
    % puts ${var name with spaces}
    contents of the variable
    % set &quot;var name with spaces&quot;
    contents of the variable
</code></pre>
Example of spaces in a procedure (function) name (the first line defines the procedure):<p><pre><code>    % proc {my space proc} {string} {puts &quot;&#x27;my space proc&#x27; called with string=&#x27;$string&#x27;&quot;}

    % {my space proc} &quot;hello how are you&quot;
    &#x27;my space proc&#x27; called with string=&#x27;hello how are you&#x27;
    % &quot;my space proc&quot; &quot;the quick brown fox&quot;
    &#x27;my space proc&#x27; called with string=&#x27;the quick brown fox&#x27;
    % set pn &quot;my space proc&quot;
    my space proc
    % $pn &quot;this that and the other&quot;
    &#x27;my space proc&#x27; called with string=&#x27;this that and the other&#x27;
</code></pre>
So there you have at least one example.