> For the complete documentation index, see [llms.txt](https://docs.b2ihealthcare.com/snowray/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.b2ihealthcare.com/snowray/reference/resources/codesystems/terminology-standards/snomed-ct/search.md).

# Advanced Search

Snowray provides an advanced search option for SNOMED CT, which can be invoked by pressing the <img src="https://content.gitbook.com/content/qCGAqlIn2vgCXJQadBh7/blobs/4qEsgUdwzLfjXfV4P99A/filter_icon.svg" alt="" data-size="line"> advanced filter icon in the search bar. This enables users to specify additional criteria to restrict their searches.

<img src="https://content.gitbook.com/content/qCGAqlIn2vgCXJQadBh7/blobs/Z8QkAuIgauxKJbagA6Ua/snomed_advanced_filter.png" alt="Advanced Search Filter" width="303">

| Field                 | Description                                                                                      |
| --------------------- | ------------------------------------------------------------------------------------------------ |
| **Term**              | Filter for concepts based on their terms                                                         |
| **Status**            | Filter for active or inactive concepts                                                           |
| **Module**            | Return concepts that are associated with the selected module                                     |
| **Namespace**         | Filter for concepts within the selected namespace                                                |
| **Ancestor**          | Return all child concepts of the selected concept                                                |
| **Semantic tag**      | Filter for concepts based on their semantic tags                                                 |
| **Active member of**  | Filter for concepts that are present in the selected resource                                    |
| **Definition status** | Return either *Defined* or *Primitive* concepts only                                             |
| **Description type**  | Return *Fully Specified Name*, *Synonym*, or *Definition* only                                   |
| **Effective time**    | <p>Search concepts by their release dates<br><em>Note:</em> time range can also be specified</p> |

The filters above are mostly dropdowns, while the [ECL](https://confluence.ihtsdotools.org/display/DOCECL) filter requires typing in a valid query. A content assist, which can be activated by pressing `Ctrl` + `Space` , helps users to construct ECL queries easily.

Once all the required filters are specified, pressing <img src="https://content.gitbook.com/content/qCGAqlIn2vgCXJQadBh7/blobs/KWQBqJNdgL4ktwik98pU/apply_button.png" alt="" data-size="line">will update the tree only with the matching results according to the filters.&#x20;

{% hint style="info" %}
Active members of a resource will only be detected correctly after the resource is synchronized, i.e. it is either released or exported to RF2.
{% endhint %}

### Search results

In case of SNOMED CT, the matching search results can be sorted based on semantic tags serving as a sort of a grouping for better overview.

<figure><img src="https://content.gitbook.com/content/qCGAqlIn2vgCXJQadBh7/blobs/NQ7IpCJzVSZy7foSzyCC/snomed_semantic_tag_sort.png" alt=""><figcaption><p>Semantig Tag Based Sorting</p></figcaption></figure>

{% hint style="info" %}
This sorting option can be accessed from the *Content display options* (<img src="https://content.gitbook.com/content/qCGAqlIn2vgCXJQadBh7/blobs/F5o3oL3RIzCmVZVtDyR3/code_system_sort_icon.svg" alt="" data-size="line">).
{% endhint %}