How do I know if a domain name has been registered or K?

Webmasters note:

How do I know if my domain name has been registered or K? In fact, domain name registration is also exquisite, the most important of which is to check whether the domain name is indexed by the search engine K. If the domain name has been registered, and the website is rejected by the search engine for reasons such as laws and regulations or spam, the registration of this domain name will have a great impact on your future website operations.

if you select a domain name that has been hacked or cheated, the evaluation of website importance has a great impact on website traffic, especially in search engines. The importance of search engines for website indexing is shared by all the users who know the website and share some of their common views. I hope this will help you.
1: First, check the registration information of the domain name in the domain name query center, such as hichina or xinnet, or where the domain name owner can be queried. http://whois.domaintools.com This website provides the query function, which is also very powerful. You can look at other functions. For example, you can use the registered domain name rqseo.com without a registration record.
If the domain name has been registered, you must be careful and check whether there are records of K.
2: Check whether there are records through (site: domain name), and then check the reverse link, using (link: domain name) or (domain: domain name) you can also go to some websites that provide reverse query connections to query, or go to the search engine to query by command. If there is reverse connection, but the site has no results, then this domain name may be K.
3: If you directly enter a website with a record, but the site has no record, K may pass the record.
4: You can view the domain name history page, the world rankings, And the Alexa ranking to see whether the domain name has been used.
5: query whether the domain name has been a website. Open http://web.archive.org/web/ enter the domain name you want to query and press take me back, data will be displayed on any website.
after confirmation, You can see whether the domain name has been registered or not. Does a search engine not include a domain name that has been replaced by K? This issue is uncertain. If you accidentally register a domain name that has been crossed by K, you should pay attention to resubmitting the website to the search engine, updating the website in a timely manner, and earnestly operating the website, the search engine will also slowly patronize and include websites.