H3C MSR 20-20 Command Reference Manual page 2101

2101
When defining rules in an IPv4 ACL, you do not necessarily assign them numbers.
The system can do this automatically in steps. For example, if the default step
applies, rules you created are automatically numbered 0, 5, 10, 15, and so on. One
benefit of rule numbering step is that it allows you to insert new rules between
existing ones as needed. For example, after creating four rules numbered 0, 5, 10,
15 in an ACL configured with the step of five, you can still insert a rule numbered
1.
Any step change can result in renumbering. For example, after you change the
step in the above example from five to two, the rules are renumbered 0, 2, 4, 6,
and 8.
Note that even if the current step is the default, performing the undo step
command can still result in rule renumbering. Suppose that ACL 3001 adopts the
default numbering step and contains two rules numbered 0 and 5. After you
insert rule 1 and rule 3, the rules are numbered 0, 1, 3, and 5. If you perform the
undo step command, they will be renumbered 0, 5, 10, and 15.
Example # Set the rule numbering step to 2 for ACL 2000.
<Sysname> system-view
[Sysname] acl number 2000
[Sysname-acl-basic-2000] step 2
# Set the rule numbering step to 2 for ACL 3000.
<Sysname> system-view
[Sysname] acl number 3000
[Sysname-acl-adv-3000] step 2
# Set the rule numbering step to 2 for ACL 4000.
<Sysname> system-view
[Sysname] acl number 4000
[Sysname-acl-ethernetframe-4000] step 2