$ ./mymakeldif.txt

cn=abc,ou=People,dc=example,dc=com
changetype: modify
delete: my_attr1
my_attr1:<order>1</order>

cn=def,ou=People,dc=example,dc=com
changetype: modify
delete: my_attr1
my_attr1:<order>1</order>

cn=jkl,ou=People,dc=example,dc=com
changetype: modify
delete: my_attr1
my_attr1:<order>1</order>

cn=mnp,ou=People,dc=example,dc=com
changetype: modify
delete: my_attr1
my_attr1:<order>1</order><code>PM23xED1</code>