This was what I originally sent:
Title: User Rank Level
Description: Used to determine which rank badge to display in user postbits.
Profile Field Category: Ranking (radio button option)
Default Value: 0
Max length of allowed user input: 2
Field Length: 2
Profile Field Type: Single-Line Text Box
Display Order: 5
Field Required: No
Field Editable by User: No
Private Field: Yes
Field Searchable on Members List: No
Show on Members List: No
Regular Expression: (leave blank)
Display Page: Options: Other
But, yes it should be:
Profile Field Type: Single-Line Text Box
And then change the following:
Max length of allowed user input: 128
Field Length: 128
Everything else is correct.