summary: Reference for OHIF Viewer URL parameters that control WorkList filtering, study/series loading, and viewer behavior, including parameters for filtering by patient name, modality, data sources, specifying initial series/instances, and selecting hanging protocols.
You can modify the URL at any state of the app to get the desired result. Here
are different part of the APP that you can modify:
## WorkList
The WorkList can be modified by adding the following query parameters:
### PatientName
The patient name can be modified by adding the `PatientName` query parameter.
```js
/?patientName=myQuery
```
### MRN
The MRN can be modified by adding the `MRN` query parameter.
```js
/?mrn=myQuery
```
### Description
The description can be modified by adding the `Description` query parameter.
```js
/?description=myQuery
```
### Modality
The modality can be modified by adding the `modalities` query parameter.
```js
/?modalities=MG
```
### Accession Number
The accession number can be modified by adding the `accession` query parameter.
```js
/?accession=myQuery
```
### DataSources
If you happen to have multiple data sources configured, you can filter the
WorkList by adding the `dataSources` query parameter.
```js
/?dataSources=orthanc
```
Note1: You should pass the `sourceName` of the data source in the configuration file (not the friendly name nor the name)
Note2: Make sure that the configuration file you are using actually includes that data source. You cannot use a data source from another configuration file.
:::tip
You can add `sortBy` and `sortDirection` query parameters to sort the WorkList
You can use this feature to open a current and prior study in the Viewer.
Read more in the [Hanging Protocol Module](../platform/extensions/modules/hpModule.md#matching-on-prior-study-with-uid) section. You can also use commas to separate
values.
:::
### SeriesInstanceUIDs
Sometimes you need to only retrieve a specific series in a study, you can do
that by providing series level QIDO query parameters in the URL such as
SeriesInstanceUIDs. This does NOT work with instance or study