There are four tags every HTML document should have. These tags define what type of document it is, and the major sections. These tags are: <HTML>, <HEAD>, <TITLE> and <BODY>.
The use some of these tags has been an ongoing source of controversy for some time. Because these tags don't have any visible effect on a web page, they seem useless. In fact, these tags are optional.
So why use them at all? The answer falls into the concept of good form. A well written HTML document not only produces a good web page, it is easy to read and understand in its "raw" form. By using the document level tags, you divide the page into logical sections, each with its own purpose. This results in a page of HTML that is easy to understand and edit.
To make the code more understandable for a programmer you may use “ignore this” tags. These tags either tell the browser to ignore sections of code, or to treat the code as plain text, not as HTML. Unfortunately, not only is HTML not completely standard, the methods of ignoring HTML is not standard. I can only recommend using this one: <!-- hidden text --> (and even that has its problems). The other tags are outdated, not widely supported, or just turned out to be bad ideas.
Do you have an idea now how to find the cache?
You can check your answers for this puzzle on Geochecker.com.