SPC096901: Do not use inline code in ASPX pages

ASPX pages should not contain inline code.

Remove the inline code and use code behind instead. MSDN: Because inline code can run with full trust on the server, it is possible for a developer to expose data from anywhere in the SharePoint environment by making a call to elevate the privileges of the code during run time. As a best practice, any inline code should therefore be reviewed for security implications before it is allowed to be installed and run on the server.

For customization rules it depends on the specific practices and guidelines of the target farm if the rules are valid or not. Disable the rule if it does not apply in your case.

• Inline Code