Yes it is! To do this:
Select the item you wish to do this for from the list and then go to view the items full profile
Click the plus sign in the ‘Information’ box
Select ‘Text’
Enter the field you wish in the name box and then enter the information in the text box, then press save
This custom field will now appear in the ‘Information’ tab
You can also choose to filter by and view custom fields in Reports.
To filter by custom fields, select Filter and choose the custom field you wish to Filter by from the dropdown menu.
To view custom fields in the columns, select Edit View then Edit Column and choose the custom field you wish to view as part of the Report.