Son of Saul is an Oscar-winning Hungarian drama film, directed by Laszlo Nemes-Jeles.

  • Version: Snow Owl v4.6
  • Release date: 8 April 2016
  • End date: 19 September 2015
  • Code name: SAUL

Snow Owl 4.6 brings various improvements in the visibility of description logic features of SNOMED CT. In addition to this, some of the core browsing and authoring features have been redesigned and enhanced based on user feedback. We’ve added new video tutorials to assist with adoption of the tool. The following release notes summarize the most significant updates since the previous publicly available release.

Description logic updates

View the stated or the inferred form of the ontology

The application can now be set to operate in authoring and browsing mode.

A new toggle button has been added that switches between authoring (stated) and browsing (inferred) views. The selected view is applied throughout the entire application.

Authoring mode: Authoring is permitted when the lock is unlocked

Browsing mode: Authoring is not permitted when the lock is locked

In the SNOMED CT navigator, the stated view displays the tree based on the manually authored stated relationships. The inferred view displays all hierarchical relationships that were calculated by the classifier, meaning that concepts may appear under more specific parents in the hierarchy. By toggling this button the user can review the the outcome of the classification process and its impact on the parent-child relationships.

By changing between the two different modes the SNOMED CT concept editor switches to display stated and additional characteristic types by selecting authoring mode or to displaying inferred characteristic types by selecting browsing mode. When authoring mode is selected, the editor allows modifications on the concept by enabling the addition of both sanctioned and unsanctioned attributes. The attribute editing fields are powered by the machine readable concept model (MRCM), where for any particular concept domain, various attribute and concrete domain constraints are specified. The editing is not limited to these attributes only, as the user can always deviate from the model if necessary. When selecting to create a new concept, the mode automatically switches to authoring mode.

The concept editor in Authoring (stated) mode

The concept editor in Browsing (inferred) mode

After the editing is completed, it is recommended to classify the concept to complete modeling. Filtering the editor to the inferred characteristic type displays all attributes that were calculated by the classifier. Additional attributes can also be selected for display per user preference.

Highlight fully defined concepts

The concept navigator now indicates fully defined concepts in bold font. This simplifies authoring using proximal primitive supertypes, which is being increasingly used within the IHTSDO to model content. It also makes identifying incompletely modeled content easily, without having to open the concept in the editor. Concepts can be quickly bookmarked from the tree view to create a worklist for concept definitions to be completed. The same visual indication of the definition status is available in the Parents view as well. A toggle button in the navigator toolbar allows switching this feature on or off.

Fully defined concepts are indicated in bold font

In addition to the SNOMED CT navigator and the Parents view, a definition status column has been added to Search results view to indicate whether a concept is fully defined or primitive by browsing the results of an ESCG or advanced search query.

Terminology search and browse updates

The SNOMED CT advanced search has been improved to simplify the input of search parameters by providing drop-downs to select valid values. The search criteria have been extended, so it is now possible to filter concepts by namespace, module, or definition status, and combine these filters with lexical search methods. The module search criterion has also been added to the SNOMED CT description and reference set searches.

The new advanced search UI

Hovering over a search field displays information about available wildcards, logical operators, etc. that can be used to find the most relevant results.

Tooltip providing hints on the syntax

To support repetitive lookups the advanced search dialog remembers the selected values from drop-down fields when the dialog is opened again after running a query.

Revamped concept tooltips

Concept tooltips in the SNOMED CT hierarchical concept navigator have been redesigned to show more detailed information on the concept, including the fully specified name, the concept ID and the module. The number of descendants is also displayed.

New tooltips on the concept navigator display more detailed info


Snow Owl broadened the range of supported terminologies by providing search, browse, and mapping capabilities for ICD-10-CM. A hierarchical navigator allows browsing through the chapters, while double-clicking a term opens a read-only editor for viewing the code and the details. Lexical search and tree filtering is also available, and ICD-10-CM codes can be used in value sets, mapping sets and SNOMED CT mapping reference sets.

ICD-10-CM hierarchical view and navigator

Searching ICD-10-CM codes

Content authoring related news

Proximal primitive modeling

Snow Owl now enables selecting the preferred modeling method by using either the proximal parent, or the proximal primitive supertype for concept authoring.

Proximal primitive parent model selects the closest primitive parent (or parents) in the hierarchy to the concept being modeled. By using this modelling method, inferred attributes from the selected concept are automatically added to the new concept as stated attributes. After running the classifier, more accurate inferred parents will be indentified. This method is recommended by the IHTSDO, as it reduces the maintenance of parent relationships and increases the accuracy and breadth of supertypes and subtypes.

The other modeling method is Proximal parent (or parents) – here the direct parent is used, regardless of its definition status. Attributes are not copied over to the new concept, as the classifier will inherit them as needed.

Both modeling options are available when creating a new child or sibling concept. After selecting the modeling option and finishing the wizard, the new concept’s editor is shown to allow modifications to the descriptions and attributes.

Choosing between proximal and proximal primitive parents in the new child concept wizard

Choosing between proximal and proximal primitive parents in the new sibling concept wizard

MRCM updates

The machine readable concept model (MRCM) defines the allowed attributes a particular concept domain can have. This model is editable and licensed users can now export their version of the concept model for sharing it with other users. An easy to use import-export wizard has been added to facilitate this process.

The MRCM editing feature is now available for demo users as well. The MRCM constraint editor has been enhanced with a quick filter functionality to ease the navigation and lookup of the rules.

Version compare

Snow Owl 3.1 introduced the versioning features for various terminologies. As moving forward with the terminology management, it is possible to tag versions that are eligible for publication. In Snow Owl 4.6 the different versions of a particular terminology can be compared to see a list of all updates (including new additions and retirements) that happened between two publication dates, or between a publication date and the present state of the terminology.

Opening the version compare wizard

Exported change details in Excel


Mapping reference set improvements

It’s now possible to create extended map type reference sets. This type of reference set it very similar to complex map type reference sets, but also allows specifying map categories for an associated reference set member. In case of ICD-10 the individual category values are subtypes of 447634004 |ICD-10 Map category value|. For further information about extended map reference set, please refer to the IHTSDO Technical Implementation Guide.

Creating an extended map type reference set

Once reference set members have been published when creating a version of SNOMED CT, it’s not possible to delete members of the reference set.

Versioned reference set members can’t be deleted

Versioned components can only be inactivated. The Clone and retire function inactivates a mapping and creates a new mapping with the same referenced component. This is useful if you want to change a mapping that has already been versioned, because you only need to define the new target. The function is available for all map type reference sets.

Cloning and retiring a mapping

Value domain, mapping set and local code system enhancements

Value domains, mapping sets and local code systems can now be exported on an individual basis, easing the distribution of limited, user-defined content. The exported output contains an index sheet that helps navigating between the different artifacts – this comes handy when a large number of value domains, mapping sets or local code systems are present.

Index sheet displaying exported value domains


Automapping now uses fuzzy matching when looking up possible matches, providing better mapping and matching power for various use cases. In addition to this, fine-tuning the search profiles also proved useful in increasing mapping efficacy.

Collaborative editing updates

The 4.6 version of Snow Owl includes a simplified task query user interface for quick lookup and organization of authoring tasks that are tied to the Bugzilla issue tracking system.

Specifying basic parameters in the query wizard

In addition to this, the task context is retained even after a task is closed, thus enabling review and verification of already completed tasks.

Education and documentation

New video tutorials

Since our last public release, we’ve added a number of video tutorials to support the adoption of Snow Owl. These video tutorials cover a broad variety of use cases from reference set authoring to the creation of a local code system, or mapping local codes to SNOMED CT. The videos are available on our YouTube channel.