When I am using the command npm install all resolved properties of npm-shrinkwrap.json append ?dl=https://registry.npmjs.org/<package-name>.
Example
...,
"@types/hammerjs": {
"version": "2.0.35",
"resolved": "https://npm.artifactory.transactdevops.com:443/artifactory/api/npm/npm-virtual/@types/hammerjs/-/hammerjs-2.0.35.tgz?dl=https://registry.npmjs.org/@types/hammerjs/-/hammerjs-2.0.35.tgz",
"integrity": "<key>",
"dev": true
},
...
The packages are from Artifactory and .npmrc does not seem to have anything to do with it.
I don't know what "dl" means and the reason this needless addition occurs, but I would like to keep a clean file when I'll add (npm i --save) or update dependencies and share those changes.