Offset-list
An offset-list is a mechanism used in distance vector routing protocols to increase metrics on incoming and outgoing routing protocol advertisements. EIGRP and RIP can both use offset-lists to modify metrics.
The syntax used for this command is the following:
offset-list {access-list-number | access-list-name} {in | out} offset [interface-type interface-number]
Any routes matching the access list will have their metrics increased by the value of offset. If the value is 0, no action is taken.
A value of 0 for the access-list-number indicates that all networks will be matched.
Links:
https://www.ciscopress.com/articles/article.asp?p=1613547&seqNum=2
https://networklessons.com/cisco/ccie-routing-switching/gre-tunnel-recursive-routing-error/