# Documentation of expression tag syntax

**URL:** <https://forum.inductiveautomation.com/t/documentation-of-expression-tag-syntax/30485>\
**Category:** Ignition\
**Created:** [December 6, 2019, 4:42am UTC](https://forum.inductiveautomation.com/t/documentation-of-expression-tag-syntax/30485 "2019-12-06T04:42:22Z")\
**Posts on this page:** 2\
**Page:** 1

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**Author:** ![silverbacknet](https://sea1.discourse-cdn.com/inductiveautomation/user_avatar/forum.inductiveautomation.com/silverbacknet/32/7385_2.png) [@silverbacknet](https://forum.inductiveautomation.com/u/silverbacknet)\
**Post date:** [December 6, 2019, 4:42am UTC](https://forum.inductiveautomation.com/t/documentation-of-expression-tag-syntax/30485/1 "2019-12-06T04:42:22Z")

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[https://docs.inductiveautomation.com/display/DOC80/Expression+Overview+and+Syntax](https://docs.inductiveautomation.com/display/DOC80/Expression+Overview+and+Syntax) would be the obvious place to include some overview of what [.] and [~] mean, but they aren’t there. As far as I can tell, they aren’t explicitly explained in the documentation anywhere.

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**Author:** ![deon.korb](https://avatars.discourse-cdn.com/v4/letter/d/8c91f0/32.png) [@deon.korb](https://forum.inductiveautomation.com/u/deon.korb)\
**Post date:** [December 6, 2019, 6:16am UTC](https://forum.inductiveautomation.com/t/documentation-of-expression-tag-syntax/30485/2 "2019-12-06T06:16:04Z")

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Hi,

They are documented here:  
[https://docs.inductiveautomation.com/display/DOC80/Understanding+Tags](https://docs.inductiveautomation.com/display/DOC80/Understanding+Tags)

Look at Using Relative Paths.

That said, the examples could be a bit more verbose.

Hope that helps.

Regards,  
Deon