Clarification on "Non-integer constants are not allowed in the ORDER BY clause in 90" Issue

Hi Guys,

We're upgrading our SQL Server database from 2005 to 2012.

I ran the Upgrade Advisory report and got this issue "Non-integer constants are not allowed in the ORDER BY clause in 90" because of the script below

SELECT
	gp.BRAND+' <> '+gp.CATEGORY AS 'full name',
	gp.PRODCODE,
	gp.CATEGORY
FROM dbo.GFK_PRODUCT gp
ORDER BY
		'full name'

I tried running the same query in our test SQL Server 2012 and it ran successfully. 

Now I'm confuse if i still need to change it

I google the issue a bit and came across this link and mentioned this

"

1.) Non-integer constants are ... constants that are not integer number.

Example: 'string1' represents a string constant

0x01 represents a varbinary constant

{ts '2015-02-26 06:00:00'} represents a datetime constant

1.23 represents a numeric constants

2) So single quotes are used to define a string constants / character string constants but SQL Server allows also to use single quotation marks use also as column identifier delimiter:

SELECT... expression AS'Column1'FROM...

In this context is clear that 'Column1' is a column identifier but when used in ORDER BY : ORDER BY 'Column1' it generates confusion because SQL Server doesn't knows if it represents a string literal (character string constant) or it represents a column identifier / column name."

Do I still need to change the existing code even though it's working fine in 2012? If yes, it is because of best practice reason or it will total get deprecated/not working in the future version?

Also, to resolve the issue I can use brackes?

ORDER BY [full name]?

Many thanks.