# Documentation for elasticsearch definitive guide **URL:** \ **Category:** Elasticsearch\ **Created:** [January 3, 2018, 3:04am UTC](https://discuss.elastic.co/t/documentation-for-elasticsearch-definitive-guide/113865 "2018-01-03T03:04:52Z")\ **Posts on this page:** 3\ **Page:** 1
**Author:** ![Jason\_Wee](https://avatars.discourse-cdn.com/v4/letter/j/7ea924/32.png) [@Jason\_Wee](https://discuss.elastic.co/u/Jason_Wee)\ **Post date:** [January 3, 2018, 3:04am UTC](https://discuss.elastic.co/t/documentation-for-elasticsearch-definitive-guide/113865/1 "2018-01-03T03:04:53Z")
when i read this [https://www.elastic.co/guide/en/elasticsearch/guide/1.x/\_important\_configuration\_changes.html](https://www.elastic.co/guide/en/elasticsearch/guide/1.x/_important_configuration_changes.html) and i switch to 2.x guide, pop up say page not found. when i search around, i got this [https://www.elastic.co/guide/en/elasticsearch/guide/2.x/important-configuration-changes.html](https://www.elastic.co/guide/en/elasticsearch/guide/2.x/important-configuration-changes.html) any significant of the underscore in the url? ---
**Author:** ![warkolm](https://sea2.discourse-cdn.com/elastic/user_avatar/discuss.elastic.co/warkolm/32/39224_2.png) [@warkolm](https://discuss.elastic.co/u/warkolm)\ **Post date:** [January 3, 2018, 3:16am UTC](https://discuss.elastic.co/t/documentation-for-elasticsearch-definitive-guide/113865/2 "2018-01-03T03:16:42Z")
> [@Jason\_Wee](#): > > any significant of the underscore in the url? Nope. ---
**Author:** ![system](https://us1.discourse-cdn.com/elastic/original/3X/1/a/1ac57faf039f6b580b3f104ef42a2a89e41014de.png) [@system](https://discuss.elastic.co/u/system)\ **Post date:** [January 31, 2018, 3:16am UTC](https://discuss.elastic.co/t/documentation-for-elasticsearch-definitive-guide/113865/3 "2018-01-31T03:16:52Z")
Closed on January 31, 2018, 3:16am UTC This topic was automatically closed 28 days after the last reply. New replies are no longer allowed.