Salesforce custom object suffixes

__c Custom Object or Custom field
__r Custom relationship field as used in a SOQL query to traverse the relationship
__ka KnowledgeArticle
__kav KnowledgeArticleVersion
__Feed Article Type Feed or Custom Object Feed
__ViewStat KnowledgeArticleViewStat
__VoteStat KnowledgeArticleVoteStat
__DataCategorySelection Article Type__DataCategorySelection
__x External Object
__xo Salesforce-to-Salesforce (S2S) spoke/proxy object
__mdt Custom Metadata Type
__Share Custom object sharing object
__Tag Salesforce Tagsbelow
__History Field History Tracking for Custom Objects
__pc Custom Person Account Field
__pr Used for traversing custom Person Account relationship fields
__hd Historical Data
__hqr, __hst Start/End of the Datetime range
__b BigObject
__latitude__s Geolocation Latitude Coordinate
__longitude__s Geolocation Longitude Coordinate
__e Platform Events - a.k.a. EventBus event (Winter `17 pilot)
__p Custom Person Object (Spring `15 pilot)