Wait, but is it ethical to promote or provide easy access to tantra-related materials? These can be considered sensitive. Should there be any content warnings or age restrictions? The user didn't mention that, but it's something to consider for compliance.
I should consider the possible challenges. Internet Archive's search can be broad, so creating a feature that filters or highlights books in Hindi on these topics could help. Also, ensuring that the PDFs are properly formatted (fixed) is another point. Maybe the current downloads are corrupted or not well-structured for some users. Wait, but is it ethical to promote or
I need to think about how to structure this feature. Maybe a custom search filter with tags like "Hindi", "tantra", "mantra", "yantra". Also, providing direct download links for PDFs. Another aspect is accessibility—ensuring the content is legally available for public domain, as Internet Archive hosts public domain works. The user might not be aware that some of these materials are in the public domain, so highlighting that could be useful. The user didn't mention that, but it's something