numeric factor with missing range
1 = strongly disagree
2 = disagree
3 = neither agree nor disagree
4 = agree
5 = strongly agree

numeric factor with long value labels
1 = abcdefghijklmnopqrstuvwxyzabcdefghijklmnopqrstuvwxyzabcdefghijklmnopqrstuvwxyzabcdefghijklmnopqrstuvwxyzabcdefghijklmnop
2 = ABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789 ! " # $ % & ' ( ) * + , - . / : ; < = > ? @ [ \ ] ^ _ ` { | } ~ €

numeric factor with coded missing values
1 = strongly disagree
2 = disagree
3 = neither agree nor disagree
4 = agree
5 = strongly agree
99 = no answer

numeric factor with duplicated factor labels
1 = A
2 = A
3 = B

numeric factor with undeclared values
1 = strongly disagree
5 = strongly agree

numeric factor with undeclared values
1 = yes
2 = no

string factor with coded missing
f = female
m = male
u = unknown

string factor with duplicated factor labels
a = A
b = A
c = C

string factor with undeclared values
n = no
y = yes