How to remove post duplicate when using query_posts(‘offset=1’)

In order to remove the duplicate posts, I used the below process in one of the theme I worked on.

  1. Create a global variable
  2. Store the post ID of first loop on the variable
  3. On next loop, use post__not_in to remove the already shown posts.

Or, you can also check if current post id is in array of global variable and skip that post.

error code: 523