# taxonomy assignment problem

**URL:** https://forum.qiime2.org/t/taxonomy-assignment-problem/20937
**Category:** Library Support
**Tags:** rescript
**Created:** [September 30, 2021, 6:20am UTC](https://forum.qiime2.org/t/taxonomy-assignment-problem/20937 "2021-09-30T06:20:54Z")
**Posts on this page:** 1
**Showing post:** 4

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### Author: ![SoilRotifer](https://forum.qiime2.org/user_avatar/forum.qiime2.org/soilrotifer/32/21071_2.png) [@SoilRotifer](https://forum.qiime2.org/u/SoilRotifer)
#### Post date: [October 1, 2021, 2:25pm UTC](https://forum.qiime2.org/t/taxonomy-assignment-problem/20937/4 "2021-10-01T14:25:15Z")

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> [@Nisha](#):
>
> Yes, I have used my own classifier. updated SILVA db (138.1)compatible with qiime2 using RESCRIPT.  
> Im using V3 region.

Great! Thanks for using RESCRIPt!

> [@Nisha](#):
>
> what identity percent it considers while annotating an OTU to a taxonomic level? Is it 100% ?

If you made the reference database yourself, and did not cluster the reference sequences, then percent identity isn't really considered (_i.e._ the reference db can be used for 100-99% and downward). That is, you can use the reference database regardless of your clustering level. For some further thoughts in this see this [post](https://forum.qiime2.org/t/pre-trained-silva-classifier-v3-v4-qiime-2021-4/20470/15).

The default approach, does not cluster the reference sequence data, it is based on the SILVA NR99 database. This is due to the reasons outlined [here](https://www.arb-silva.de/projects/ssu-ref-nr/). However, you can change the options for `rescript get-silva-data` to download the full reference database. You could certainly cluster your reference sequences yourself by modifying the `rescript dereplicate` parameters, say at 97%. Your reference sequence would then "consider" 97% similarity.

-Mike

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