# Pattern Replace Character Filter In a Normalizer
**URL:** https://discuss.elastic.co/t/pattern-replace-character-filter-in-a-normalizer/271669
**Category:** Elasticsearch
**Created:** [April 29, 2021, 2:58pm UTC](https://discuss.elastic.co/t/pattern-replace-character-filter-in-a-normalizer/271669 "2021-04-29T14:58:46Z")
**Posts on this page:** 2
**Page:** 1
### Author:  [@MilanGatyas](https://discuss.elastic.co/u/MilanGatyas)
#### Post date: [April 29, 2021, 2:58pm UTC](https://discuss.elastic.co/t/pattern-replace-character-filter-in-a-normalizer/271669/1 "2021-04-29T14:58:46Z")
My goal is to have a same pattern replace character filter on both my custom analyzer and normalizer. Seems like I can use the filter on the analyzer without issues, however facing error when trying to attach the filter to the normalizer:
> Custom normalizer [lowercase\_custom] may not use filter [custom\_trim].
I have found almost exact problem being discussed at [Normalizers poor support for token filters and missing docs · Issue #28605 · elastic/elasticsearch · GitHub](https://github.com/elastic/elasticsearch/issues/28605). However based on discussion at [normalizers to support pattern\_replace char filter · Issue #23142 · elastic/elasticsearch · GitHub](https://github.com/elastic/elasticsearch/issues/23142) I understood that pattern replace character filter shall be now supported on the normalizers, thus I am confused.
We are using Elasticsearch version 7.9.
PS: We want our custom\_trim character filter to trim also line-breaking whitespace, we have found out that the trim filter is not removing e.g. the \u2007 character
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### Author:  [@system](https://discuss.elastic.co/u/system)
#### Post date: [May 27, 2021, 2:59pm UTC](https://discuss.elastic.co/t/pattern-replace-character-filter-in-a-normalizer/271669/2 "2021-05-27T14:59:25Z")
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