Ping options - Ingress versus Source?

[riedmueller]

I am exploring the various options for the Ping command, and I can't find any details on the difference between the INGRESS and SOURCE keywords. Other than INGRESS asking for an interface only, while SOURCE allows for either an address or an interface, they seem to be the same. Does the router process the ping differently somehow? (note I'm seeing this on a 4221 running 16.9.4).

Thanks for any insight!

[emergismsh]

I have a C1111 (V9.16.12) 
You may find a difference when you add acl in access-group in and out.
Pingning with source ip is successful even if acl as deny entries 
Pingning with ingress respect the acl strategy 
Although, I have created a service request to clarify this as all of my other device configs are with source IP strategy...