Well, as stated, the message “No Grammar Constraints (DTD Or XML schema)” is just a warning. But even so, some of us may find it annoying to see that warning icon even though it really does not halt or disrupt the compilation process.

To disable this message in Eclipse, do the following steps:

• Go to Windows > Preferences
• Go to XML > XML Files > Validation
• Select “ignore” in the drop down selection of “No grammar specified”
• Press OK

You may have to clean your project or restart Eclipse if ever the warning icons still persist.