“Deprecated” is a term used in programming to describe when a function or other feature should no longer be used.
Because of the fact that the term “deprecated” is fairly industry-specific to programming, we choose instead to call it “decapitated”. We think this is a more accurate description.
“Deprecated ” is often used in PHP because of he numerous iterations PHP has gone through. PHP describes many functions as deprecated because they were used in PHP 4 but were dumped in PHP 5. PHP also has many significant upgrades between version – subversions that have many more differences than average. PHP 5.3 is a great example of this, but there are many more significant sub-versions.
Within a PHP application there can also be “deprecated” (or “decapitated”) features. When a programmer or programmers write an application, there is a very good chance that programmer will have to come back at some point – even if it’s weeks, months or years later – to add fixes, and make changes and upgrades. In the process of making fixes, a programmer must make those fixes backwards compatible with the existing system. This is why “backwards compatible” and “deprecated” are very closely related. The programmer will often have no choice but to implement the new code separately but alongside the existing/preview code. The programmer will have to leave the old code in there so existing features will not break.
A feature will remain implemented but deprecated for a long time, whether it’ s a native PHP function or a custom function in your application. The point at which it is completely removed, and goes from being “deprecated” to “unsupported” is completely arbitrary. Often in order to prevent it from being used, it will be completely removed form the documentation prior from being removed from the application. This way, it becomes harder to find information on it, harder to use it, and easier to phase out.