Also, when I click on a feature, it shows all attribute fields. Now I repeated the process but it appeared some problems. The first lines which contains numbers is not appearing with a letter in front, like in the first screen, but like this: Also, when I click on the feature, it doesn't appear the fields that I've added from the excel, but only the primary ones. Now, I removed all symbols that ArcGIS doesn't like from the excel, but with all that, I don't know what to do in order to overcome this problem. I know that it's something easy but I'm beginner and all this little issues can became very annoying because of my misunderstanding.