There are actually two main rules for scientific names, not four. These rules govern the binomial nomenclature system, which is a standardized way of naming species:

1. Genus and Species: Each scientific name consists of two parts: the genus (a broader group) and the species (a specific type within that genus).

* For example, *Homo sapiens* is the scientific name for humans, with *Homo* being the genus and *sapiens* the species.

2. Latinization and Italics: Scientific names are typically written in Latin, even if they are derived from other languages. They are always italicized when written.

* This standardization ensures that scientific names are understood globally, regardless of language differences.

Additional Considerations:

* Authority: The name of the scientist who first described the species is often included after the species name, often abbreviated. For example, *Homo sapiens* Linnaeus, meaning Linnaeus was the first to describe humans scientifically.

* Capitalization: The genus name is always capitalized, while the species name is not.

* Uniqueness: Each scientific name should be unique and refer to only one species.

While these are the fundamental rules, there are also additional guidelines and procedures for naming new species, which are overseen by organizations like the International Code of Nomenclature for algae, fungi, and plants (ICN) and the International Code of Zoological Nomenclature (ICZN).