Table:
0
A
B
C
D
1
document type code
document type name
document type description
reference document types
2
BK
Book
excellent
3
CV
CV
excellent
4
PT
Presentation
very good
5
PP
Paper
good
6
FM
Film
fun

Questions and formulas:
Question: What are the document type codes, names and descriptions?
Formula: UNIQUE(HSTACK(A1,B1,C1))
Formula2: UNIQUE(HSTACK(A2:A6,B2:B6,C2:C6))
Level: easy
Question: Show films' descriptions
Formula: UNIQUE(CHOOSECOLS(FILTER(A1:D1,B1="film"),3))
Formula2: UNIQUE(CHOOSECOLS(FILTER(A2:D6,B2:B6="film"),3))
Level: medium
Question: What is description for films?
Formula: UNIQUE(CHOOSECOLS(FILTER(A1:D1,B1="film"),3))
Formula2: UNIQUE(CHOOSECOLS(FILTER(A2:D6,B2:B6="film"),3))
Level: medium