[iliaal]

Summary

• Correct the historical changelog claim that borderStyle() and borderColor() enter getter mode with omitted/null arguments.
• Document their existing successful no-op behavior and direct readers to the per-side getters; align the two parameter annotations with their nullable integer signatures.
• Documentation only: native code, stubs, and non-comment PHP tokens are unchanged.

Validation

• Verified all 300 default-branch blobs and file modes before editing; published tree equals the locally reviewed tree, with all modes preserved and only the two intended files changed.
• Fresh strict native shared build: -Wall -Wextra -Wno-unused-parameter -Wimplicit-fallthrough -Werror, zero diagnostics.
• Full PHPT suite: 254 passed, 7 skipped, 0 failed, 0 warned (261 total).
• 12 focused XLS/XLSX setter/no-op cases passed, including distinct side values and both omitted and explicit-null arguments.
• All 12 API-reference PHP lints passed; changed reference file has identical non-comment tokens.
• git diff --check, independent review, and merge-tree check passed. No open sibling PRs at publication.

Limits

Local validation used PHP 8.4.26 NTS and LibXL 5.2.0.1 trial on Linux with retained configure headers; no fresh phpize/configure, sanitizer, cross-platform or performance measurements. Seven existing environment/license skips are not passes. Exact-head GitHub Actions completed successfully: all 36 executed jobs passed across Tests and Windows Build. All executed job logs were inspected, with zero PHPT failures; the release-only attachment job was skipped, not counted as a pass.