Capitalise industry labels, drop LinkedIn and sparse social columns

Industry now uses standard casing. LinkedIn URL and the five columns populated for under 1% of rows are removed. Card links to stackscan.com reduced to citation, attribution and contact.

README.md

@@ -32,24 +32,12 @@ dataset_info:
       dtype: float64
     - name: Industry
       dtype: string
-    - name: LinkedIn URL
-      dtype: string
     - name: Locality
       dtype: string
     - name: Country
       dtype: string
     - name: TLD
       dtype: string
-    - name: Language
-      dtype: string
-    - name: Instagram
-      dtype: string
-    - name: Twitter
-      dtype: string
-    - name: YouTube
-      dtype: string
-    - name: TikTok
-      dtype: string
     - name: SPF
       dtype: string
     - name: DMARC
@@ -69,14 +57,12 @@ dataset_info:
 
 ## Overview
 
-This dataset records which of 36,120 large organizations publish SPF and DMARC records on their primary domain, with firmographic context for each: industry, employee band, country, locality, founding year and LinkedIn profile.
+This dataset records which of 36,120 large organizations publish SPF and DMARC records on their primary domain, with firmographic context for each: industry, employee band, country, locality and founding year.
 
 SPF lists the servers allowed to send mail for a domain. DMARC tells receiving servers what to do with mail that fails that check, and where to send reports. A domain with SPF but no DMARC has published the list without publishing an instruction, so receivers are left to decide for themselves.
 
 Collected in August 2026. DNS records change, so treat the data as a snapshot of that month rather than a current state.
 
-Full statistics are published at StackScan for [DMARC](https://www.stackscan.com/technology/dmarc) and [SPF](https://www.stackscan.com/technology/spf-sender-policy-framework).
-
 ## SPF and DMARC Coverage
 
 Of the 35,563 large organizations that publish SPF, **45.7% also publish DMARC**. The other 19,315 publish SPF alone.
@@ -109,13 +95,13 @@ By industry, same threshold:
 
 | Industry | Organizations | DMARC |
 | -------- | ------------- | ----- |
-| defense & space | 168 | 56.5% |
-| medical devices | 197 | 55.8% |
-| banking | 650 | 55.5% |
-| airlines/aviation | 252 | 54.0% |
-| insurance | 638 | 53.4% |
-| security and investigations | 318 | 35.5% |
-| professional training & coaching | 150 | 28.7% |
+| Defense & Space | 168 | 56.5% |
+| Medical Devices | 197 | 55.8% |
+| Banking | 650 | 55.5% |
+| Airlines/Aviation | 252 | 54.0% |
+| Insurance | 638 | 53.4% |
+| Security and Investigations | 318 | 35.5% |
+| Professional Training & Coaching | 150 | 28.7% |
 
 Employee band makes little difference. Organizations with 5,001 to 10,000 employees reach 46.7%, and those with more than 10,000 reach 44.9%.
 
@@ -123,32 +109,24 @@ BIMI and MTA-STS are rare in this population. Across all 36,120 organizations, 1
 
 ## Dataset Fields
 
-`Email-Authentication.csv`, 36,120 rows, 20 columns. Coverage is the share of rows where the field is populated.
+`Email-Authentication.csv`, 36,120 rows, 14 columns. Coverage is the share of rows where the field is populated.
 
 | Column | Type | Coverage | Description |
 | ------ | ---- | -------- | ----------- |
 | `Popularity Rank` | int64 | 95.1% | Website popularity rank, lower being more popular. Rows are stored in ascending rank order |
-| `Domain` | string | 100% | Primary website domain. Unique across the file |
-| `Company Name` | string | 100% | Organization name, lowercased |
-| `Company Size` | string | 100% | Employee band. Two values: `5001-10000` and `10001+` |
+| `Domain` | string | 100.0% | Primary website domain. Unique across the file |
+| `Company Name` | string | 100.0% | Organization name, lowercased |
+| `Company Size` | string | 100.0% | Employee band. Two values: `5001-10000` and `10001+` |
 | `Year Founded` | float64 | 71.2% | Founding year |
-| `Industry` | string | 99.1% | Industry label, lowercased |
-| `LinkedIn URL` | string | 100% | Organization LinkedIn profile path |
+| `Industry` | string | 99.1% | Industry label |
 | `Locality` | string | 79.7% | City or region, where available |
-| `Country` | string | 100% | Organization or website country |
-| `TLD` | string | 100% | Top-level domain |
-| `Language` | string | sparse | Detected site language |
-| `Instagram` | string | sparse | Instagram handle |
-| `Twitter` | string | sparse | Twitter handle |
-| `YouTube` | string | sparse | YouTube channel |
-| `TikTok` | string | sparse | TikTok handle |
-| `SPF` | string | 100% | `yes` or `no` |
-| `DMARC` | string | 100% | `yes` or `no` |
-| `BIMI` | string | 100% | `yes` or `no` |
-| `MTA-STS` | string | 100% | `yes` or `no` |
-| `Posture` | string | 100% | `SPF only`, `SPF + DMARC` or `DMARC without SPF` |
-
-The language and social columns are populated for fewer than 1% of rows.
+| `Country` | string | 100.0% | Organization or website country |
+| `TLD` | string | 100.0% | Top-level domain |
+| `SPF` | string | 100.0% | `yes` or `no` |
+| `DMARC` | string | 100.0% | `yes` or `no` |
+| `BIMI` | string | 100.0% | `yes` or `no` |
+| `MTA-STS` | string | 100.0% | `yes` or `no` |
+| `Posture` | string | 100.0% | `SPF only`, `SPF + DMARC` or `DMARC without SPF` |
 
 ## Methodology
 
@@ -204,7 +182,7 @@ BibTeX:
 
 The files in this repository are CC BY 4.0 and free for anyone to use, including commercially. No request or permission is needed.
 
-StackScan also provides free access to larger and custom datasets for data journalists, academic researchers, non-profits and other organizations working on non-commercial projects. Ask through [stackscan.com](https://www.stackscan.com/technology/dmarc).
+StackScan also provides free access to larger and custom datasets for data journalists, academic researchers, non-profits and other organizations working on non-commercial projects. Ask through [stackscan.com](https://www.stackscan.com).
 
 ## License