Method

Sources

Every technical statement on the site links to the published source it comes from, such as a textbook, course notes or a manufacturer's document. The full list, with the date each was read, is on the sources page.

Drawings

Every symbol is drawn for this site, in US and IEC style. None is copied from a standard, from drawing software or from another website.

Dates

The date at the foot of a symbol page is when its facts were last checked against their sources.

Corrections

To report a mistake, use the contact page. Each correction is checked against a source before the page changes.