# Terminology for MPLS Topics

Certain terms used with MPLS, such as the names of messages, are often expressed in the RFCs and other sources either with initial uppercase letters or all uppercase letters. For improved readability, those terms are represented in lowercase in this chapter. Table 49 lists the terms and some of their variant spellings.

Table 49: Conventions for MPLS Terms

In This Chapter | In RFCs and Other Sources
--- | ---
ack | Ack | ACK
bundle | Bundle | –
hello | Hello | HELLO
initialization | Initialization | INITIALIZATION
keepalive | Keepalive | KEEPALIVE
label mapping | Label Mapping | LABEL_MAPPING
label release | Label Release | LABEL_RELEASE
label request | Label Request | LABEL_REQUEST
label request abort | Label Request Abort | LABEL_REQUEST_ABORT
label withdrawal | Label Withdrawal | LABEL_WITHDRAWAL
message ack | message_Ack | MESSAGE_ACK
message ID | message_ID | MESSAGE_ID
srfresh | Srefresh | –
path | Path | PATH
patherr | PathErr | PATHERR
pathtear | PathTear | PATHTEAR
resv | Resv | RESV
resvconf | ResvConf | RESVCONF
resverr | ResvErr | RESVERR
resvtear | ResvTear | RESVTEAR
targeted hello | Targeted Hello | TARGETED_HELLO

#### Related Documentation

- MPLS Terms and Acronyms
- MPLS Overview