For example, consider a simple entry with two multi-valued mail attributes.

dn: uid=test,dc=example,dc=com 
objectclass: inetorgperson 
cn: test user 
sn: user
description: oldDescription 
mail: test@yahoo.com 
mail: test@gmail.com

Then, apply the following changes to the entry.

dn: uid=test,dc=example,dc=com 
changetype: modify 
add: mail 
mail: test@hotmail.com
- 
delete: mail 
mail: test@yahoo.com 
- 
replace: description 
description: newDescription

The resulting changelog would record the following attribute values.

dn: changeNumber=1,cn=changelog 
objectClass: top 
objectClass: changeLogEntry 
targetDN: uid=test,dc=example,dc=com 
changeType: modify
changes::
YWRkOiBtYWlsCm1haWw6IHRlc3RAaG90bWFpbC5jb20KLQpkZWxldGU6IG1haWwKbWFpbDogdGVzdEB5YWh 
vby5jb20KLQpyZXBsYWNlOiBkZXNjcmlwdGlvbgpkZXNjcmlwdGlvbjogbmV3RGVzY3JpcHRpb24KLQpyZX 
BsYWNlOiBtb2RpZmllcnNOYW1lCm1vZGlmaWVyc05hbWU6IGNuPURpcmVjdG9yeSBNYW5hZ2VyLGNuPVJvb
3QgRE5zLGNuPWNvbmZpZwotCnJlcGxhY2U6IGRzLXVwZGF0ZS10aW1lCmRzLXVwZGF0ZS10aW1lOjogQUFB 
QkxxQitIaTQ9Ci0KAA==
ds-changelog-before-values:: ZGVzY3JpcHRpb246IG9sZERlc2NyaXB0aW9uCm1haWw6IHRlc3RAeW
Fob28uY29tCm1haWw6IHRlc3RAZ21haWwuY29tCmRzLXVwZGF0ZS10aW1lOjogQUFBQkxxQjdaZ1E9Cm1vZ
GlmaWVyc05hbWU6IGNuPURpcmVjdG 9yeSBNYW5hZ2VyLGNuPVJvb3QgRE5zLGNuPWNvbmZpZwo=
ds-changelog-after-values:: ZGVzY3JpcHRpb246IG5ld0Rlc2NyaXB0aW9uCm1haWw6IHRlc3RAZ21
haWwuY29tCm1haWw6IHRlc3RAaG90bWFpbC5jb20KZHMtdXBkYXRlLXRpbWU6OiBBQUFCTHFCK0hpND0KbW
9kaWZpZXJzTmFtZTogY249RGlyZWN0b3J5IE1hbmFnZXIsY249Um9vdCBETnMsY249Y29uZmlnCg== 
ds-changelog-entry-key-attr-values:: dWlkOiB0ZXN0Cg== 
changenumber: 1

Run the bin/base64 decode -d command line tool to view the decoded value for the changes, ds-changelog-before-values, and ds-changelog-after-values attributes.

After base64 decoding, the changes attribute displays the following.

add: mail 
mail: test@hotmail.com 
- 
delete: mail 
mail: test@yahoo.com 
- 
replace: description 
description: newDescription 
- 
replace: modifiersName 
modifiersName: cn=Directory Manager,cn=Root DNs,cn=config 
- 
replace: modifyTimestamp 
modifyTimestamp: 20131010020345.546Z 
-

After base64 decoding, the ds-changelog-before-values attribute displays the following.

description: oldDescription 
mail: test@yahoo.com 
mail: test@gmail.com
modifyTimestamp: 20131010020345.546Z 
modifiersName: cn=Directory Manager,cn=Root DNs,cn=config

After base64 decoding, the ds-changelog-after-values attribute displays the following.

description: newDescription
mail: test@gmail.com 
mail: test@hotmail.com 
modifyTimestamp: 20131010020345.546Z 
modifiersName: cn=Directory Manager,cn=Root DNs,cn=config