Without rules, there'd be no structure. This principle applies to every form of endeavor poetry inclusive. Although there are no officially encoded rules of poetry, following popular rules help to enhance productivity and structure.
It is not mandatory to follow the rules all the time because, in poetry  (which is art) breaking the rules intentionally and strategically can become an art form, thus drawing attention and expressing deeper meaning. It is believed that rule-breaking sometimes has the effect of helping readers to find several messages within a poem that is short.
What are other examples of rules in poetry?
Some rules to consider besides those already mentioned are:
- Keeping form
- moderation with literary devices
- authenticity
See the link below for more about Rules of Poetry:
https://brainly.com/question/1342511