# Dissect filter special character "\\" "\<"
**URL:** https://discuss.elastic.co/t/dissect-filter-special-character/163571
**Category:** Logstash
**Created:** [January 9, 2019, 3:46pm UTC](https://discuss.elastic.co/t/dissect-filter-special-character/163571 "2019-01-09T15:46:19Z")
**Posts on this page:** 5
**Page:** 1
### Author:  [@Necus](https://discuss.elastic.co/u/Necus)
#### Post date: [January 9, 2019, 3:46pm UTC](https://discuss.elastic.co/t/dissect-filter-special-character/163571/1 "2019-01-09T15:46:19Z")
Hi,
I'm trying to use the best of dissect, unfortunately i have encounter small problem with special characters like "" or "\<"
For example:
\<14\>Jan 9 15:36:03
and
domain\_name\username
When i'm parsing this log with fields, i wan't to exclude "\<14" and "domain\_name\" in the example above.
Do you have any idea how to do this?
---
### Author:  [@Badger](https://discuss.elastic.co/u/Badger)
#### Post date: [January 9, 2019, 4:48pm UTC](https://discuss.elastic.co/t/dissect-filter-special-character/163571/2 "2019-01-09T16:48:05Z")
As far as dissect is concerned, the only special characters are %{ and }. So if you have a string such as
```
<14>Jan 9 15:36:03 and domain_name\username and so on
```
You can dissect it using
```
dissect { mapping => { "message" => "<%{a}>%{ts} %{+ts} %{+ts} and %{d}\%{u} %{}" } }
```
---
### Author:  [@Necus](https://discuss.elastic.co/u/Necus)
#### Post date: [January 9, 2019, 6:36pm UTC](https://discuss.elastic.co/t/dissect-filter-special-character/163571/3 "2019-01-09T18:36:22Z")
Thank you that obviously works 🙂
But that creates new question, how to change this parser if there is no domain and username field, its empty, now I have \_dissectfailure tag ☹
I believe its because of the "" character
---
### Author:  [@Badger](https://discuss.elastic.co/u/Badger)
#### Post date: [January 9, 2019, 7:35pm UTC](https://discuss.elastic.co/t/dissect-filter-special-character/163571/4 "2019-01-09T19:35:32Z")
As the [documentation](https://www.elastic.co/guide/en/logstash/current/plugins-filters-dissect.html#_conditional_processing) says, you might need to test the format of the string is appropriate for the dissection before dissecting.
---
### Author:  [@system](https://discuss.elastic.co/u/system)
#### Post date: [February 6, 2019, 7:35pm UTC](https://discuss.elastic.co/t/dissect-filter-special-character/163571/5 "2019-02-06T19:35:41Z")
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