Short rules of genizah

I’m an Ashkenazi Jew (I know there is a difference between different communities in this issue). I work in the field of advertisement. I’d like to receive some information about the laws of genizah (laws whereby it’s forbidden to treat holy objects and writings with disrespect). What is genizah? Are a few words or a picture genizah? Would appreciate a concise summary of the laws.

In short, the rules are as follows:

1. Three or more words from a scriptural verse need to be buried.
2. But if the verse is written as an allegory or a citation, it doesn’t need to be buried.
3. If there is a verse in a picture, then these rules apply to it as well.
4. The name of Hashem has to be buried even if it’s written or copied separately from other text.
5. If Hashem’s name is written as “ה'”, one should be stringent and bury it. But if it’s written as “ד'”, then it doesn’t have to be buried.