It varies from country to country. The most recent major change in US law was 1998.
Copyleft is the practice of using copyright law to offer the right to distribute copies and modified versions of a work and requiring that the same rights be preserved in modified versions of the work. In other words, copyleft is a general method for making a program (or other work) free (libre), and requiring all modified and extended versions of the program to be free as well.
You cannot use a modified version of Agatha Christie's poem legally as her work is still under copyright protection. Copyright protection typically lasts for the author's life plus 70 years, so you would need to seek permission from the copyright holder or estate to use any part of her work in your fanfiction.
Wikipedia content is licensed under Creative Commons. The date that the page was last modified is at the very bottom of each page.
If a work is within the public domain, it means that work may be used or modified or republished by any person, without need for royalties or fear of copyright infringement.
"Copyright in fragment" is a common misspelling of "copyright infringement," which is the violation of copyright.
In some cases a software author will decide to make his/her program available to the public at no charge. This is usually termed "freeware" and although free is still protected by copyright. It cannot be duplicated, redistributed, or modified, for anything other than personal use, without permission.
The copyright date for Wikipedia pages, including Red Skelton's, typically reflects the year the content was last updated or modified. Wikipedia itself operates under a Creative Commons license, which means the content can be freely shared and adapted, but the specific copyright date can vary. To find the exact date for Red Skelton's Wikipedia page, it's best to check the page's edit history directly on the site.
license agreement
"A copyright attorney provides legal counsel regarding copyright law. A copyright attorney could be an asset in assisting a client obtain and registering a copyright, transfering ownership of a copyright, helping avoid copyright violations, and protecting the client's own copyright. Although any attorney may counsel regarding copyright law, copyright attorneys can be a great asset where specific copyright issues are addressed."
The only way for someone to claim copyright in a family crest is if that person created the crest, or substantially modified it, or is the heir of someone who did that and who died less than 75 years ago. Crests and other symbols may be protected in some countries by their laws protecting Heraldic symbols, but that is not copyright.
No. Names, titles, and common words/phrases do not qualify for copyright protection. Under some circumstances they can be registered as trademarks, however.
Copyright is a noun, or an adjective as in the phrase "copyright protection."