> For the complete documentation index, see [llms.txt](https://chembl.gitbook.io/chembl-data-deposition-guide/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://chembl.gitbook.io/chembl-data-deposition-guide/~/revisions/t4ziM1Dk3kUY0U850C3g/file-structure/loader-model.md). # Simplified input data schema This diagram is a minimal example of the data schema. It shows only the fields which are **mandatory (in bold)**, strongly recommended, or which are required to link data together within or between files. Fields with a \* are a primary key. RIDX is a **mandatory** field in any file that includes it. Without including your RIDX, records cannot be linked to your references and data loading will fail. There are additional fields which are not mandatory, which are outlined in the [Field names and data types](/chembl-data-deposition-guide/~/revisions/t4ziM1Dk3kUY0U850C3g/file-structure/field-names-and-data-types-minimal-data-submission.md) section.