> For the complete documentation index, see [llms.txt](https://doc.sysdevmobile.com/mss-extensibility/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://doc.sysdevmobile.com/mss-extensibility/mss-5.0/mss-extension-functions-mss-kalipso/transport-document/3900-transport-document-open-module.md).

# 3900 - (Transport Document) Open Module

3900 - (Transport Document) Open Module

| Event   | Extension action set  | Description                                                     |
| ------- | --------------------- | --------------------------------------------------------------- |
| Before  | EXT\_3900\_1\_Before  | Will be executed before MSS open the Transport Document module; |
| Replace | EXT\_3900\_2\_Replace | Will replace MSS Transport Document module;                     |
| After   | EXT\_3900\_3\_After   | Will be executed after closing the Transport Document module;   |