Hello. We have a problem in the migration of ezPublish 5.4.14 to eZPlatform 2.5 in the migration of custom tags for Online Editor.
https://doc.ez.no/eZ-Publish/User-manual/5.x/The-Online-Editor/Settings/Configuration-settings-ezoe_attributes.ini#type

Before in the RTE we had a "LinkType" fieldType for the custom tags:

[CustomAttribute_imageGallery_gallery]
Name=Gallery
Title=Select the Gallery object.
Type=link
LinkType[]
LinkType[eznode://]=Link to a gallery object

We used it for relation inside custom tag to some internal content objects, but now in the new version of eZPlatform there is no ability to use such attributeType.

Here is a list of allowed types from the code:

const CUSTOM_TAG_ATTRIBUTE_TYPES = ['number', 'string', 'boolean', 'choice'];

We should have GUI interface like earlier to have an ability to select from the tree.