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name: editing-obo-ontologies description: Skills and tools for editing OBO format ontologies, including querying terms, checking out/checking in individual terms, and following OBO format conventions. Do not use this if the source for the ontology you are editing is not in obo format (e.g. ofn)

OBO Ontology Editing Guide

This skill provides guidance and tools for editing ontologies in OBO format.

Project Layout Conventions

Most OBO ontologies follow a similar structure:

• Main development file is typically src/ontology/{ontology}-edit.obo
• Individual terms can be checked out to terms/ directory for editing
• Some projects may have different layouts - check the project's documentation

Querying Ontology Terms

Use the obo-grep.pl script for searching OBO files:

• Look at a specific term by ID:
  • obo-grep.pl --noheader -r 'id: ONTO:0004177' src/ontology/{ontology}-edit.obo
• All mentions of an ID:
  • obo-grep.pl --noheader -r 'ONTO:0004177' src/ontology/{ontology}-edit.obo
• Search by regex (e.g., all mentions of hand or foot):
  • obo-grep.pl --noheader -r '(hand|foot)' src/ontology/{ontology}-edit.obo
• Search is much faster than full file reads
• ONLY search the main edit file (usually src/ontology/{ontology}-edit.obo)
• DO NOT do manual greps or read entire files unless necessary

Before Making Edits

• Read the request carefully and make a plan, especially if there is nuance
• If a PMID is mentioned, try to read it using: aurelian fulltext PMID:NNNNNN
• This also works for DOIs and URLs for scientific papers (if accessible)
• ALWAYS check proposed parent terms for consistency
• Check project-specific guidelines if available

Editing Workflow

IMPORTANT: Use Checkout/Checkin for Large Files

• Do not edit large ontology files directly
• Use the checkout/checkin workflow for individual terms
• Check out a term: obo-checkout.pl src/ontology/{ontology}-edit.obo ONTO:1234567 [OTHER_IDS]
• This creates a single stanza file: terms/{ontology}_1234567.obo (note: colon replaced with underscore)
• Edit the small file in the terms/ folder
• Check back in: obo-checkin.pl src/ontology/{ontology}-edit.obo ONTO:1234567 [OTHER_IDS]
• Checking in updates the edit file and removes the file from terms/
• You can edit multiple terms in one batch file if needed

Scripts Available

This skill includes three essential scripts:

1. obo-grep.pl - Fast searching of OBO files
2. obo-checkout.pl - Extract terms to individual files for editing
3. obo-checkin.pl - Merge edited terms back into main file

All scripts are available in your PATH when this skill is loaded.

OBO Format Guidelines

Basic Structure

• Term ID format: ONTO:NNNNNNN (check project conventions for number of digits)
• Each term requires:
  • id: - unique identifier
  • name: - human-readable label
  • namespace: - ontology namespace
  • def: - definition with references in square brackets
• Use standard relationship types: is_a, part_of, has_part, etc.
• Follow existing term patterns for consistency

Handling New Term Requests (NTRs)

• Check project conventions for temporary ID ranges
• Example: Some projects use ranges like ONTO:777xxxx for new terms
• Always check for ID clashes: grep 'id: ONTO:777' src/ontology/{ontology}-edit.obo
• NEVER guess ontology IDs - use search tools to find actual terms
• NEVER guess PMIDs for references - do web searches if needed

Citations and References

• Cite publications appropriately: def: "..." [PMID:nnnn, doi:mmmm]
• Fetch full text when needed: aurelian fulltext <PMID:nnn> (also works with DOIs and URLs)
• All synonyms should include proper citations
• Never use empty brackets [] without a source

Synonyms

Synonyms should include proper attribution:

Correct:

synonym: "alternative name" EXACT [PMID:12345678]
synonym: "abbrev" EXACT ABBREVIATION [PMID:12345678]

Relationships and Logical Definitions

• All terms should have at least one is_a parent
• Logical definitions follow genus-differentia form
• Text definitions should mirror logical definitions
• Include source attribution for relationships when based on literature:

Logical Definitions (intersection_of)

Example of proper intersection_of usage:

[Term]
id: ONTO:0000715
name: specific disease
def: "A general disease that involves specific location." [PMID:12345678]
is_a: ONTO:0001082 ! general disease
intersection_of: ONTO:0004971 ! general disease
intersection_of: disease_has_location UBERON:0000029 ! specific location

Note that in OWL this corresponds to: 'specific disease' EquivalentTo 'general disease' and 'disease has location' some 'specific location'

Obsoleting Terms

• Obsolete terms should have NO logical axioms (is_a, relationship, intersection_of)
• Obsolete terms may have one replaced_by tag (exact replacement)
• Or multiple consider tags (suggested alternatives)
• Always include obsolescence reason and tracker reference

Example of simple obsolescence:

[Term]
id: ONTO:0100334
name: obsolete term name
property_value: IAO:0000231 OMO:0001000
property_value: IAO:0000233 "https://github.com/{project}/issues/XXXX" xsd:anyURI
is_obsolete: true
replaced_by: ONTO:0100321

Example with considerations instead of replacement:

[Term]
id: ONTO:0100229
name: obsolete term name
def: "OBSOLETE. Original definition here." [original references]
property_value: IAO:0000231 OMO:0001000
property_value: IAO:0000233 "https://github.com/{project}/issues/XXXX" xsd:anyURI
is_obsolete: true
consider: ONTO:0100259
consider: ONTO:0100260

Important Notes on Obsolescence

• Synonyms and xrefs can be migrated to replacement terms judiciously
• Never do complete merges with alt_id - use obsolescence with replacement instead
• No relationships should point to an obsolete term
• When obsoleting, you may need to rewire other terms to "skip" the obsoleted term

Metadata Best Practices

• Link to issue trackers: property_value: IAO:0000233 "https://github.com/{project}/issues/XXXX" xsd:anyURI
• Sign new terms (don't tag pre-existing terms):

  property_value: http://purl.org/dc/terms/creator https://orcid.org/0000-0001-2345-6789
  

• All terms should have definitions with at least one reference (preferably PMID)
• Dates are typically auto-generated by build processes

Syntax Checking

Validate OBO syntax using ROBOT:

robot convert --catalog src/ontology/catalog-v001.xml \
  -i src/ontology/{ontology}-edit.obo \
  -f obo \
  -o {ontology}-edit.TMP.obo

Use -vvv flag for full stack trace if there are errors.

Design Patterns

Many OBO ontologies use DOSDP (Dead Simple Ontology Design Patterns):

• Check src/patterns/dosdp-patterns/*.yaml for project-specific patterns
• Follow existing patterns when creating similar terms
• Common patterns include:
  • Location-based disease patterns
  • Gene-related disease patterns
  • Part-of hierarchies
  • Abnormality patterns

Important Reminders

• NEVER guess identifiers of any kind
• If you include an identifier not provided by the user, you MUST verify it
• PMIDs can be checked with aurelian or web search
• Always follow project-specific conventions and check existing examples
• When in doubt, ask for clarification rather than making assumptions