What are Meta tags? We are asked this question all the time. Meta tags are snippets of informational code that have been located between your <HEAD> </HEAD> tags that are a part of the HTML document you’ve generated.
There are two known styles/attributes that you’ll see for Meta tags. These are:
1. <META HTTP-EQUIV=”name” CONTENT=”content”>
2. <META NAME=”name” CONTENT=”content”>
In the mid 90s, Meta tags were developed to assist with the rapid growth of web pages. In the late 90’s there was a major occurrence. Many Webmasters, generally those who ran adult-orientated websites, began to abuse the use of Keyword Meta tags. Many unrelated keywords were placed on their sites in the Meta tag section, causing their pornographic sites to begin appearing in search results unrelated to topics such as “Smithsonian”.
Eventually the major search engines began discontinuing the use of Meta tags as major criteria for listing sites. Google had always ignored the use of Meta tags, and currently will only index Google Meta Tags. There are several searches that do read Meta tags in their own way. I have another article on Google Tags if you are looking for information specific to Google.
These meta tags can control the behavior of search engine crawling and indexing. The robots meta tag applies to all search engines, while the “googlebot” meta tag is specific to Google. The default values are “index, follow” (the same as “all”) and do not need to be specified.
We understand the following values (When specifying multiple values, separate them with a comma):
noindex: prevents the page from being indexed
nofollow: prevents the Googlebot from following links from this page
nosnippet: prevents a snippet from being shown in the search results
noodp: prevents the alternative description from the ODP/DMOZ from being used
noydir: prevents the alternative description from the Yahoo! Directory from being used
noarchive: prevents Google from showing the Cached link for a page.
noimageindex: lets you specify that you do not want your page to appear as the referring page for an image that appears in Google search results.
What do you mean by “noydir,noodp” in terms of Meta Tag?
The noydir and noodp are Meta Robots commands that instruct search engine bots on how to handle the usage of data for your site in the Yahoo! Directory and the Open Directory Project/DMOZ Directory.The noydir command corresponds to the Yahoo! Directory and the noodp command correlates to DMOZ.
When a site is listed in the Yahoo! Directory there is a title and description associated with that listing. So, Yahoo! started showing that title and description as the linking text and snippet text in the search engine results page (SERP) whenver that website would show up (most commonly only the homepage). The noydir command overrides this functionality and gives control back to the website owner to control the linking and snippet text in the SERPs via the Title tag and Meta Description tag on their website. By regaining this control you can adjust those fields whenever desired.
The same functionality goes for the noodp command. However, this is directed at Google. Google partnered with ODP to power the Google Directory so if you website was listed in DMOZ then Google would pull that listing information as the linking and snippet text in the Google SERPs. The noodp overrides that functionality and give you control back.
The most common implementation is to do both commands simultaneously as in your question like such:
<meta name=”robots” content=”noydir,noodp” /> (content field order does not matter)
They can also be listed separately as such:
<meta name=”robots” content=”noydir” />
<meta name=”robots” content=”noodp” />
You can also direct the commands to the specific bots as such:
<meta name=”googlebot” content=”noodp” />
<meta name=”slurp” content=”noydir” />
The list of Meta Tag Attributes:
1.Meta Content Language
2.Meta Content Type
C. Non-Recommended Tags:
4.Meta Pragma No-Cache
8.Meta Resource Type
9.Meta Revisit After
12. Meta Cache-Control