Declaring multiple variable on one line is difficult to read.
Noncompliant code example
DECLARE @aaa AS INTEGER = 5, @bbb AS INTEGER = 42, @ccc AS CHAR(3) = 'foo' -- Noncompliant
Compliant solution
DECLARE @aaa AS INTEGER = 5
DECLARE @bbb AS INTEGER = 42
DECLARE @ccc AS CHAR(3) = 'foo'