deletions | additions       diff --git a/abbrvshortnat.bst b/abbrvshortnat.bst  index 9ba635a..9c58b1f 100644  --- a/abbrvshortnat.bst  +++ b/abbrvshortnat.bst 
...
}  %if$  %format.issn output  if $ if$  format.doi output  format.url output  new.block