If you added a Code Specification to a Component, you are able to specify the behavior of that component on code level.
The Code Specification View also provides Syntax-Checking and marks invalid code with a little red error-marker. Move your mouse over this error-marker and you will get an info-text about at which position in the code the error is found and what kind of error it is. Only the first error in your code is marked. If you remove this error, the next error will be marked.
Things to note: