How do effect html and image protection the listings

[Fred]

Hello,
How do effect html and image protection measurements the listings
in search engines.

Securing the html code or image porotection might hinder
the crawlers to detect the pages propertly?

Thank you for any info and programmes to this.

Fred

[Edgar]

Well some do and others don't. Which type of html and image protection are you talking about?

[HealthInfo]

The robots still read the alt, so robot.txt disallowing images has no real reduction in listing.