External Documents and the acceptable handling thereof

1 - Do I need to keep an explicit record, or may I argue that I can request any registered document from our Service desk? 
I require advice which external documents are required for the ISMS. Your colleague wrote:
“Examples of external documents are laws and regulations you need to comply with, documentation sent by your customers or suppliers, etc.
The identification of such documents can be made during identification of ISMS requirements and risk assessment.” 
The only external documents that we identified as pertaining to our ISMS might be the auditors reports and certificates.

Answer: Please note that if you can ensure the availability of registered documents stored in your Service Desk you do not need to keep a record on your own.

2 - Which “identification of ISMS requirements and risk assessment.” Is your colleague referring to?

I leave my questions at that. I am looking forward to some clarification and will continue from that.

Answer: Please note that “identification of ISMS requirements and risk assessment” are mandatory steps in the implementation of your ISO 27001 ISMS, and during these steps, you can identify needs to keep specific records.

For example, when identifying ISMS requirements, you may find that you need to comply with a law (e.g., EU GDPR), and for that, you need to keep some records (e.g., user consent for data processing). Additionally, during risk assessment, for the controls you find applicable, you will need to identify records to be kept for evidencing controls implementation (e.g., backup test report).

For further information, see:
- ISO 27001 implementation checklist https://advisera.com/27001academy/knowledgebase/iso-27001-implementation-checklist/