I have a piece of text and HTML Code that I repeatedly use in almost every post. I would like to store it at a central location and refer to it much like a shortcode. That is, in a post, I may include something like [mycode] and the associated piece of text and HTML code would be automatically displayed within that post.
This is so that when there is a need to make any amendment to the code, all previous posts that refer to it will be updated with the change.
May I know how that can be done?