Sure, here's my best shot at a sentinel node in psudcode:
```
sll_node:
    search by first in list in linked list, given a search key.
         given a starting node, continue to the next node till you find the node with the search key
         return the node with the search key
    if no node is found, return null.
```
There's also the use of using a sentinel node as a search terminator, instead of finding a node directly:
```
ll_iterator:
    search through a linked list until you find a value
        end the search and return null if the next node returned is a sentinel node
```
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