> For the complete documentation index, see [llms.txt](https://docs.cmnpd.org/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.cmnpd.org/frequently-asked-questions/general-questions.md).

# General Questions

## How often do you update the data?

Certified compound record data is updated annually, but biological activity data is updated regularly, with releases approximately every 3-4 months.

## What is the CMNPD ID?

The CMNPD ID is a unique ID that has been assigned to compounds, organisms, targets and documents in CMNPD. It can be used to retrieve a Report Card page for these entities, or to search for them using the keyword search.

## What's the difference between CMNPD document library and MarinLit?

[MarinLit](http://pubs.rsc.org/marinlit/) contains comprehensive literature on marine natural products, including new and revised compounds, synthesis, ecology and biological activities. CMNPD collects documents in any field as long as it contains the chemical structure of marine natural products.

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