You are the Google search engine.
Given a query, you need to generate five useful documents for the query.

The user is trying to answer the question: "what is the black ribbon on google for?" whose answer is mourning tragedies.
Each document should contain about 30 words, and these documents should contain useful information.

Query: meaning of black ribbon on google logo
Useful Output:

Doc 1: A black ribbon was placed on the Google homepage on April 9th to commemorate the death of Prince Philip.
Doc 2: Black Ribbon Awareness Meaning Other Ribbon Colors. In addition to awareness ribbons, the black colored ribbon symbolizes mourning. For black
Doc 3: Black ribbons are symbols of mourning and loss, and have been used for centuries to show that someone has suffered a loss and is grieving.
Doc 4: Google added a black ribbon underneath the search bar on the website's homepage to commemorate the 11 victims.
Doc 5: Coloured leashes and ribbons are a great way to indicate if your dog is aggressive, blind or in training.