'+' operator with one operand! How does '+' operator behave in following statement?

select + 'taco';  --Result is 'taco'


Is it doing string concatenation with first string blank ('' + 'taco'), or does it mean something else?
How does '+' operator behave in following statement?


It is parsed as a unary plus, and ignored.

The following was given in answer to Connect item 718176 on the subject (Connect has since been retired, and no archive of this page is available):


  
    After some investigation, this behavior is by design since + is an unary operator. So the parser accepts "+ , and the '+' is simply ignored in this case.
    
    Changing this behavior has lot of backward compatibility implications so we don't intend to change it &amp; the fix will introduce unnecessary changes for application code.
  




(Community Wiki answer generated from a comment on the question by Martin Smith)