This tag should be used to differentiate questions about the importation of a range of data from other questions on this site. Use when the topic is the IMPORTRANGE function. Should generally be used in conjunction with a tag for a specific app.
The Google Doc editors Help page for this function is at https://support.google.com/docs/answer/3093340.
The 50 instance call limit (that applied to 'old' sheets) no longer exists for Google 'New' Sheets.