# Filebeat fields.yml
**URL:** https://discuss.elastic.co/t/filebeat-fields-yml/171605
**Category:** Beats
**Tags:** filebeat
**Created:** [March 9, 2019, 6:28pm UTC](https://discuss.elastic.co/t/filebeat-fields-yml/171605 "2019-03-09T18:28:11Z")
**Posts on this page:** 5
**Page:** 1
### Author:  [@2ps](https://discuss.elastic.co/u/2ps)
#### Post date: [March 9, 2019, 6:28pm UTC](https://discuss.elastic.co/t/filebeat-fields-yml/171605/1 "2019-03-09T18:28:11Z")
When specifying our fields.yml, I had several questions:
1. How do we specify what should be the default time field for kibana?
2. Is there any way to specify the moment.js format for the date field for kibana?
3. What, if any, is the significance of the `key` in grouping fields?
Any help would be appreciated
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### Author:  [@kvch](https://discuss.elastic.co/u/kvch)
#### Post date: [March 13, 2019, 4:40pm UTC](https://discuss.elastic.co/t/filebeat-fields-yml/171605/2 "2019-03-13T16:40:07Z")
1. The default time field can be set on the UI. But Filebeat puts its timestamp under the field `@timestamp`. It is already added to the fields.yml of a Beat. See: [https://github.com/elastic/beats/blob/master/libbeat/\_meta/fields.ecs.yml#L9](https://github.com/elastic/beats/blob/master/libbeat/_meta/fields.ecs.yml#L9)
2. Let me ping one of my colleagues about this.
3. I am not sure I understand your question. What grouping do you mean?
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### Author:  [@kvch](https://discuss.elastic.co/u/kvch)
#### Post date: [March 13, 2019, 5:02pm UTC](https://discuss.elastic.co/t/filebeat-fields-yml/171605/3 "2019-03-13T17:02:45Z")
1. Right now there is no way to do it. But we are working on it.
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### Author:  [@2ps](https://discuss.elastic.co/u/2ps)
#### Post date: [March 14, 2019, 11:46am UTC](https://discuss.elastic.co/t/filebeat-fields-yml/171605/4 "2019-03-14T11:46:26Z")
@kvch: thank you so much for responding! for 3, in the libbeat fields.yml example that you linked to, you'll see this at the top level of the fields.yml file:
```auto
- key: ecs
title: ECS
description: ECS Fields.
fields:
```
What are `key`, `title` and `description` for? What impact do these values have on either (1) my filebeat configuration or (2) the setup of the elasticsearch index?
Finally, is there some way to specify that a dynamic mapping, like all fields not specified in the yaml be treated as unanalyzed?
For (1), yes, we figured, we just hate that we have to touch each logging index pattern for each application separately. Maybe there is a kibana API that lets us create the index patterns?
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### Author:  [@system](https://discuss.elastic.co/u/system)
#### Post date: [April 11, 2019, 11:46am UTC](https://discuss.elastic.co/t/filebeat-fields-yml/171605/5 "2019-04-11T11:46:27Z")
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