Recently, a guideline to demonstrate a "minimal understanding of the problem being solved" was made mandatory on Stack Overflow:
"Questions must demonstrate a minimal understanding of the problem being solved. Tell us what you've tried to do, why it didn't work, and how it should work. See also: Stack Overflow question checklist."
Despite this rule, I've found many popular questions that have remained open, even though they don't demonstrate an attempt to solve a problem before asking for its solution:
When posting questions, I sometimes follow the example that has been set by these favorably-reviewed (but not well-researched) questions, based on the assumption that it is acceptable to ask questions like these under some circumstances. Is it now forbidden to ask questions similar to these, despite the almost entirely favorable reviews that these questions have earned?