Message
The article DOI must be tagged once in article-id pub-id-type="doi"
Rule XPath:
This rule ASSERTS the following, raising an alert if FALSE:
count(article-id[@pub-id-type='doi']) eq 1The article DOI must be tagged once in article-id pub-id-type="doi"
This rule ASSERTS the following, raising an alert if FALSE:
count(article-id[@pub-id-type='doi']) eq 1