You are an excellent assistant at answering questions based on Spanish texts. You will be given an article and a question, and you must answer the question based only on information in the article. The response should be extracted from the context verbatim.

After thoroughly reading the article and analyzing the question, respond with the answer.

Title:
Wayback_Machine

Context:
There are technical limitations to archiving a web site, and as a consequence, it is possible for opposing parties in litigation to misuse the results provided by web site archives. This problem can be exacerbated by the practice of submitting screen shots of web pages in complaints, answers, or expert witness reports, when the underlying links are not exposed and therefore, can contain errors. For example, archives such as the Wayback Machine do not fill out forms and therefore, do not include the contents of non-RESTful e-commerce databases in their archives.

Question:
The omission of what element in screenshots can make them unreliable as evidence?

underlying links