Source: https://www.civo.com/learn/migrating-your-ingresses-in-k3s-1-20

Kubernetes version 1.20+ introduces the networking.k8s.io API version as stable. If you have ingresses that predate K3S 1.20, you have until Kubernetes 1.22 to update them. Until then, if you use old-style ingress definitions, you will receive a warning like Warning: networking.k8s.io/v1beta1 Ingress is deprecated in v1.19+, unavailable in v1.22+; use networking.k8s.io/v1 Ingress when you apply the ingress to a cluster.

first one

apiVersion: v1
data:
  file1.yaml: |+
    parameter1=value1
kind: ConfigMap
metadata:
  name: my-configmap

second one

apiVersion: v1
data:
  file1.yaml: |-
    parameter1=value1
kind: ConfigMap
metadata:
  name: my-configmap

what is the difference between |+ and |- ?