Evidence — SoftwareApplication JSON-LD is now opt-in (2026-08 fleet audit, finding C1)

_includes/content/jsonld-software.html emitted a SoftwareApplication JSON-LD graph on every consumer's homepage. The payload is hardcoded to this theme, so on any other site it was factually wrong in machine-readable form.

The problem

The include is wired unconditionally into _includes/core/head.html (line 127), gated only on page.permalink == "/". Its payload hardcodes:

Field	Value emitted on every consumer homepage
@type	SoftwareApplication / DeveloperApplication
name	{{ site.title }} — the consumer's own name
alternateName	jekyll-theme-zer0
codeRepository	https://github.com/bamr87/zer0-mistakes
downloadUrl	https://rubygems.org/gems/jekyll-theme-zer0
installUrl	the theme's own GitHub quick-start anchor
license	MIT, isAccessibleForFree: true, price: 0
featureList	12 entries describing the theme's features
screenshot	the theme's mascot image
Person node	a specific named author + their GitHub and X profiles, referenced as the site's publisher

Live consequence found in the audit: bashconsultants.com — a Denver IT consulting practice — told search engines and any JSON-LD consumer that it was a free, MIT-licensed, RubyGems-distributed developer tool authored by someone else. It had not overridden the include; there was no way to.

The include's own header stated its purpose was "to accurately cite and describe the zer0-mistakes Jekyll theme as a SoftwareApplication entity" — written for the theme's own marketing site, but shipped to everyone.

What changed

File	Change
_includes/content/jsonld-software.html	Renders only when site.jsonld_software_application is true (and the page is the homepage). Homepage detection moved into an explicit _is_homepage assign — Liquid has no parentheses and evaluates and/or right-to-left, so the combined condition would have been fragile. Header rewritten to say the block describes THE THEME, not the site rendering it.
_config.yml	Sets jsonld_software_application: true with a comment explaining that only the theme's own site may truthfully claim it. Behaviour on this site is unchanged.

Consumers need to do nothing: absent config is falsey, so the block simply stops rendering. Their standard SEO metadata (jekyll-seo-tag's own WebSite block) is untouched — see the graph_node_types in metrics.json.

Measured result

Two real builds of this repo, identical but for the flag. The opt-out column is exactly what every consumer homepage emitted before this change, since the include was previously ungated.

	theme's own site (opt-in)	consumer default (opt-out)
ld+json blocks	2	1
graph node types	WebPage, WebSite, SoftwareApplication, Person, WebSite	WebSite
false software claim	present	gone
hardcoded Person node	present	gone
homepage bytes	294,601	290,843 (−3,758)

Full numbers in metrics.json.

How to reproduce

# Opt-in (this repo's own site — schema present)
bundle exec jekyll build --config '_config.yml,_config_dev.yml' -d /tmp/optin

# Opt-out (simulates any consumer — schema absent)
printf 'jsonld_software_application: false\n' > /tmp/off.yml
bundle exec jekyll build --config '_config.yml,_config_dev.yml,/tmp/off.yml' -d /tmp/consumer

grep -c '"@type": "SoftwareApplication"' /tmp/optin/index.html     # 1
grep -c '"@type": "SoftwareApplication"' /tmp/consumer/index.html  # 0

No screenshots: this change touches <head> structured data only and has zero visual effect. The rendered page is byte-identical apart from the removed <script type="application/ld+json"> block.

Regression test: ../../features/jsonld-software-optin.spec.js — asserts the opted-in site emits exactly one valid SoftwareApplication graph describing this theme, that the homepage gate still holds, and that the payload stays internally consistent.