HTML Fragment ID Name Collision Audit

Description

Audit exact cross-namespace collisions between supplied HTML IDs and legacy named anchors with both source index lists; no browser target resolution.

HTML form controls combine attribute values, option state and form-owner references with browser-maintained DOM state. These tools take explicit strings, lists and flags so a particular relationship can be checked in isolation. The supplied-record model does not itself inspect a document or reproduce every browser state transition.

Audit exact cross-namespace collisions between supplied HTML IDs and legacy named anchors with both source index lists; no browser target resolution.

When to use this tool

Use this tool to audit exact cross-namespace collisions between supplied HTML IDs and legacy named anchors with both source index lists; no browser target resolution.

How to use the tool and how it works

Enter ids, names using the field definitions below.
Run the operation. Correct input errors before interpreting an output.
Read result.collisions. Use the ordering, boundary rules and absence conditions described below.

Find exact strings present in both the supplied ID list and name list, returning matching ID and name indexes for each first-seen shared string.^[1]

Input field	Meaning and units	Accepted input
ids	Supplied ID attribute strings.	Dense list of at most 128 strings, each at most 8,192 UTF-16 code units.
names	Supplied name attribute strings.	Dense list of at most 128 strings, each at most 8,192 UTF-16 code units.

Output field	Interpretation
result	Object containing the named fields below.
result.collisions	Shared ID/name spellings with all corresponding original indexes.

json

{
  "input": {
    "ids": [
      "a",
      "a"
    ],
    "names": [
      "a",
      "b"
    ]
  },
  "output": {
    "result": {
      "collisions": [
        {
          "value": "a",
          "idIndexes": [
            0,
            1
          ],
          "nameIndexes": [
            0
          ]
        }
      ]
    }
  }
}

Limitations and assumptions

The tool does not inspect element types, tree order or a browser’s fragment-target resolution rules.
All DOM-related facts are supplied by the caller. No element is queried, no browser state is mutated and no document-wide validity or accessibility audit is performed.
Every declared top-level input field is required and unexpected fields are rejected. Ordinary strings are limited to 8,192 UTF-16 code units and lists to 128 entries, with tighter operation-specific bounds where stated. JSON text has bounded nesting and node counts.
Numeric outputs must be finite and no larger in absolute magnitude than the safe-integer limit; operations returning exact large integers use decimal text. Positions are zero-based and spans end exclusively unless the operation explicitly states a different convention.

Alternative or Complementary methods

Use DOM inspection or browser constraint-validation APIs when actual document state matters. The supplied-record checks are useful for focused audits but do not replace a complete browser algorithm.

References

Tool behavior and example: HTML Fragment ID Name Collision Audit — tool.io

Similar or alternative tools

HTML Form Associated Owner Reference
Resolve a supplied explicit form attribute before a supplied ancestor form; missing/duplicate owner evidence is retained, no DOM lookup or first-element claim.
HTML Option Selected State Reconciliation
Reconcile explicit option selected flags for a static single/multiple select; last selected wins in single mode and first defaults, excluding disabled-option and live-dirty-state behavior.