Información que nos ha sido muy útil

Caracteres HTML

https://html.spec.whatwg.org/multipage/named-characters.html#named-character-references
https://www.utf8-chartable.de/unicode-utf8-table.pl?start=8192&number=128
https://unicode.org/emoji/charts/full-emoji-list.html
https://www.mclibre.org/consultar/htmlcss/html/html-unicode-simbolos.html

El protocolo HTTP

Tipos MIME

Configuración de Apache

https://httpd.apache.org/docs/current/es/howto
Redireccionar todas las llamadas http a https
Configurar Multiples Dominios en un servidor Apache

El protocolo Apache CGI

https://helpx.adobe.com/coldfusion/cfml-reference/reserved-words-and-variables/cgi-environment-cgi-scope-variables.html
http://www6.uniovi.es/~antonio/ncsa_httpd/cgi/env.html

API REST

https://www.oscarblancarteblog.com/2018/12/03/metodos-http-rest/
https://docs.couchdb.org/en/stable/intro/curl.html
https://dev.to/moz5691/method-override-for-put-and-delete-in-html-3fp2
https://stackoverflow.com/questions/5162960/should-put-and-delete-be-used-in-forms
https://www.restapitutorial.com/lessons/httpmethods.html

JSon

https://jsoneditoronline.org/
https://jsonformatter.curiousconcept.com/
https://jsonplaceholder.typicode.com/

ADO y Bases de Datos

https://www.connectionstrings.com/
https://docs.microsoft.com/en-us/office/client-developer/access/desktop-database-reference/ado-methods

Librerias JavaScript

https://cdnjs.com/
https://printjs.crabbly.com/

Creación y Visualización de PDFs

https://mozilla.github.io/pdf.js/
https://pdfobject.com/
https://parall.ax/products/jspdf