• Leader
• Directory
• Variable Fields

• Variable Control Fields
• Variable Data Fields

• Number and Code Fields (01X-04X)
• Classification and Call No. Fields (05X-08X)
• Heading Fields (1XX-8XX)
• Main Entry Fields (1XX)
• Title and Title related Fields (20X-24X)
• Edition, Imprint, Etc. Fields (25X-28X)
• Physical Description, Etc. Fields (3XX)
• Series Statement Fields (4XX)
• Note Fields (5XX)
• Subject Access Fields (6XX)
• Added Entry Fields (70X-75X)
• Linking Entry Fields (76X-78X)
• Series Added Entry Fields (80X-83X)
• Holdings, Location, Alternate Graphics, Etc. Fields (841-88X)

a - Increase in encoding level
c - Corrected or revised
d - Deleted
n - New
p - Increase in encoding level from prepublication

a - Language material
c - Notated music
d - Manuscript notated music
e - Cartographic material
f - Manuscript cartographic material
g - Projected medium
i - Nonmusical sound recording
j - Musical sound recording
k - Two-dimensional nonprojectable graphic
m - Computer file
o - Kit
p - Mixed materials
r - Three-dimensional artifact or naturally occurring object
t - Manuscript language material

a - Monographic component part
b - Serial component part
c - Collection
d - Subunit
i - Integrating resource
m - Monograph/Item
s - Serial

# - Full level
1 - Full level, material not examined
2 - Less-than-full level, material not examined
3 - Abbreviated level
4 - Core level
5 - Partial (preliminary) level
7 - Minimal level
8 - Prepublication level
u - Unknown
z - Not applicable

# - Non-ISBD
a - AACR 2
i - ISBD
u – Unknown

# - Not specified or not applicable
a - Set
b - Part with independent title
c - Part with dependent title