Is there any special meaning for numbers in braces like {0} or {1} in LDIF files of OpenLDAP?
It's for list ordering: Attributes or entities with the same key are sorted using the number in the braces. Especial need for access control lists, as the ordering of the rules matters, e.g.

olcAccess: {0}to attrs=userPassword,shadowLastChange 
    by self write 
    by dn="cn=admin,dc=mobikat,dc=net" write 
    by anonymous auth 
    by * none
olcAccess: {1}to * 
    by self read 
    by dn="cn=admin,dc=mydomain,dc=net" write 
    by dn="cn=readonly,dc=mydomain,dc=net" read 
    by * none