When it comes to the language of the land, Instagram is as much of a wild terrain as Twitter.

Unless you're posting a several-hundred-word screed like Justin Bieber, you want to keep your captions and comments short and to the point. It's no fun typing at length on a phone keyboard. That brevity—mixed with the common practice of using hashtags to milk attention—has led to a great deal of shorthand on Instagram.

Earlier, we looked at the most popular tags on Instagram. Most of those, like #love, #me, #cute, #girl, and #photooftheday, are pretty straightforward: They're common words or names. Celebrities, for instance, can be tagged millions of times, especially One Direction members. Other tags are merely there because some users can't help but tag every single word in a caption.

But a number of terms and acronyms may seem odd unless you're in the know. Save this cheat sheet in your bookmarks, print it out, or better yet, Instagram it and save it as your phone's screensaver. Oh yeah, and let us know if there are any important terms we're missing.

repost, #repost

Quite simply, someone's taken a photo from another Instagram user and reshared it with their followers. Often, this is accompanied by a shoutout (more on that in a bit), though not always is.

#shoutout

When you're giving someone a shoutout, it is usually accompanied by their Instagram handle. It's more often than not an attempt to help a friend (or a stranger who's done you a solid) gain more followers.

#tbt 

This stands for Throwback Thursday, perhaps the most popular ongoing weekly tag. Instagramers use this to share images from the past, which is apt given the community's proclivity to make photos as vintage-looking as possible through filters.

#l4l, #likeforlike

Two of several reciprocal tags, #l4l lets others know that you'll like one of their photos if they "heart" one of yours. Who, after all, doesn't like to be liked?


Photo by @zhelaaa/Instagram

#f4f, #follow4follow

You follow me, and I'll follow you. Simple.

#c4c, #comment4comment

This one tells your followers: Leave a remark on one of my photos, and I'll drop a comment on one of yours.

#s4s, #shareforshare

This reciprocal tag is a little more complex if you want to follow its instruction. Sharing an Instagram photo isn't the easiest thing to do. It requires you to either screenshot your Instagram feed and crop a photo to the correct size, or to grab the image from your computer and send it to your phone. Either way, if you use #s4s or #shareforshare, you're telling others to feel free to share one of your photos for a repost from you.

N.B. #s4s can also stand for "shoutout for shoutout." An inescapable issue with generic acronyms.

#fslc

This stands for "Follow, shoutout, like, comment," as Instagramers urge others to carry out all four social actions.

#icant, #icanteven, #dying, #dead, #crying

These generally mean someone's found a post particularly hilarious or shocking, rendering them to the point of apparent immobility. 

#icantbreathe

As with above, except mainly used to denote someone's hotness and the ensuing shortness of breath.

#bw

Using this means you're adding your image to a collection of black and white shots. That effect is usually achieved through the Willow or Inkwell filters, though other photo editing apps have that option too. Related tags include #monotone, #bwwednesday,  #insta_bw, #bw_lover, and #bw_society.


Photo by @trygveskogrand/Instagram

#all_shots

More than 16 million photos have this tag, one that's used add Instagramer's photos to an intended stream of all images. There are variants on this tag, such as #all_shots_members (for participants in the de facto all_shots community) and #all_shots_bw (for momochrome images).

#hkig

It stands for "Hong Kong Instagram," largely used by those in the special administrative region of China. Others, however, can co-opt the popular tag in an attempt to get more likes and followers for themselves.

Photos via @omar_velazquez/Instagram, @IndianRose_/Instagram